Index Astartes:Silent Hunters poll

[Naoki the curseblood 99]

Hello there i am in the process of planning fan made chapter but I am wondering whether i shoud make them a legion a lost one to be precise or a successor chapter to either the night lords or the raven guard please reply with your suggestions thank you for time and have a nice day

[Bjorn Firewalker]

You can cloak this Chapter with the same ambiguities regarding the Carcharodons, who have people asking, "Are they aberrant Raven Guard Marines, or loyalist Night Lords?"

 

Just remember to think long and hard on what excuse you'll use to explain why the Inquisition hasn't already purged this Chapter for "Suspicion of being Traitor Marines." You know others will demand that explanation.

[Naoki the curseblood 99]

Well in the past they explanation for if they were night lord successors was simple they tried to exterminate them and while the chapter may of escaped but their previous homeworld was destroyed in the process and they had taken heavy casualties

[Bjorn Firewalker]

Well in the past they explanation for if they were night lord successors was simple they tried to exterminate them and while the chapter may of escaped but their previous homeworld was destroyed in the process and they had taken heavy casualties

That kind of experience will make any person angry enough to turn traitor, for a chance at revenge- in which case, you might as well move this thread to the Liber Chaotica. The destruction of one's own home is NOT an act that encourages feelings of loyalty.

[Naoki the curseblood 99]

Well thats part of the idea i had in mind if i were to make them night lord successors and i have not decided on this yet

[Naoki the curseblood 99]

I see your point but i haven't fully decided on this so i can guess that was a vote for them being a night lord successor

Lost legion: 0

Night lord: 1

Raven guard: 0

[Bjorn Firewalker]

It's not a vote for the Silent Hunters being a Night Lords successor, nor is it a vote for them being a Raven Guard successor- you've revealed nothing concrete about the Chapter, so I know too little about these Marines to comment. You might as well ask me which of the two individuals with unpronounceable names deserves to be President of a former Soviet Socialist Republic I've never heard of.

 

I must admit "Silent Hunters" is an awesome name, though.

[Naoki the curseblood 99]

It's not a vote for the Silent Hunters being a Night Lords successor, nor is it a vote for them being a Raven Guard successor- you've revealed nothing concrete about the Chapter, so I know too little about these Marines to comment. You might as well ask me which of the two individuals with unpronounceable names deserves to be President of a former Soviet Socialist Republic I've never heard of.

 

I must admit "Silent Hunters" is an awesome name, though.

My sincere apologies i'll write up something about them if they were to be a night lord successor chapter i'll send you it when i'm done

[Naoki the curseblood 99]

i think i've decided they'll be a night lord successor as it'll be easier to do so i'll start a new subject onto Liber Chaotica for it 

[Naoki the curseblood 99]

Update

I've decided to rewrite the lore where they do not serve chaos but are still Renegades thus I'm moving the topic of the chapter back here my sincere apologies for any confusion caused by this change

[Bjorn Firewalker]

Update

I've decided to rewrite the lore where they do not serve chaos but are still Renegades thus I'm moving the topic of the chapter back here my sincere apologies for any confusion caused by this change

If they're renegades, you may as well leave their IA in the Liber Chaotica. It's not like the Imperium- which has ZERO tolerance for dissent- will ever knowingly allow the Silent Hunters to remain in Imperial territory.

 

If you want to keep the Silent Hunters in the Liber Astartes- among the LOYALIST Chapters- you can "have your cake and eat it too" by having the Silent Hunters fight a Chapter war, i.e., the Chapter tears itself apart in internecine conflict, with half the Silent Hunters turning renegade, while the other half remains loyal to the Imperium.

 

As for why the Imperium doesn't kill the surviving Silent Hunter loyalists "just in case," the Inquisition itself fights internecine conflicts all the time. Blame the treason on a radical Inquistor's deception, swear to aid the radical's rival in the Inquisition, offer an archeotech prize to a Magos or other boon to win over the AdMech, and they'll survive, if with greatly reduced autonomy. I doubt a competent Inquisitor will send the Silent Hunter loyalists to hunt the Chapter's renegades, due to the question, "Are these 'loyalists' all loyalists, or will there be among them those who, due to previously existing bonds of brotherhood, will warn the renegades of the Inquisition's approach? No, best keep them far, far away from the renegades, to minimize the risk."

Edited February 12, 2018 by Bjorn Firewalker

[Naoki the curseblood 99]

 

Update

I've decided to rewrite the lore where they do not serve chaos but are still Renegades thus I'm moving the topic of the chapter back here my sincere apologies for any confusion caused by this change

If they're renegades, you may as well leave their IA in the Liber Chaotica. It's not like the Imperium- which has ZERO tolerance for dissent- will ever knowingly allow the Silent Hunters to remain in Imperial territory.

If you want to keep the Silent Hunters in the Liber Astartes- among the LOYALIST Chapters- you can "have your cake and eat it too" by having the Silent Hunters fight a Chapter war, i.e., the Chapter tears itself apart in internecine conflict, with half the Silent Hunters turning renegade, while the other half remains loyal to the Imperium.

As for why the Imperium doesn't kill the surviving Silent Hunter loyalists "just in case," the Inquisition itself fights internecine conflicts all the time. Blame the treason on a radical Inquistor's deception, swear to aid the radical's rival in the Inquisition, offer an archeotech prize to a Magos or other boon to win over the AdMech, and they'll survive, if with greatly reduced autonomy. I doubt a competent Inquisitor will send the Silent Hunter loyalists to hunt the Chapter's renegades, due to the question, "Are these 'loyalists' all loyalists, or will there be among them those who, due to previously existing bonds of brotherhood, will warn the renegades of the Inquisition's approach? No, best keep them far, far away from the renegades, to minimize the risk."

i thought the liber chaotica was only for those who served chaos but you have given me an idea I'll write about the renegade members in the liber chaotica while i write about the loyalists in the liber astartes here perhaps the loyalists are in denial still believing that they are sons of corax whist the renegades have accepted that they desend from both konrad curze and the twin primarchs alpharius and omagon

[Doctor Perils]

Okey dokey, sorry to have missed this for so long, but I'll try and give my view:

I think that a potential successor of a chaos legion is entirely feasible.

 

Until last year, I'd have probably agreed with Bjorn on how little doubt the Imperium is inclined to allow before destroying a chapter of dubious descent (and therefore in their minds, loyalty).

However, the Gathering Storm and 8th edition fluff has shed a certain amount of light on just how dire the situation of the Imperium is - until now, it had always seemed that the monolithic might of the galaxy, while beset on all sides, was pretty much standing strong, and only the advent of new threats (tyranids, necron, tau, 13th black crusade etc.) were starting to make the ship rock. In fact, with storylines like the Beast Arises and the Black Legion trilogy, we have seen how frail the Imperium truly is, right from the closing days of the Scouring. The events of the Gathering Storm would have been enough to topple the whole edifice, if it weren't for the rebirth of a Primarch.

In light of this, we look again at how other chapters of dubious origin have been treated in the past: the Carcharadons for instance are greeted by loyalist chapters after their exile millenia long with mistrust, yes, but aren't actively persecuted; the Minotaurs (whose geneseed is not only suspect, it was given them during the Cursed Founding) have been to war with loyal chapters and disappeared from Imperial records for some time, and yet they were not hunted down either; the Silver Skulls and Blood Ravens have elements in their nature and history suggesting they could be of Traitorous descent, and yet the Imperium never seems to look too closely at their past; even in the case of the Badab War, when Huron appointed himself the leader of his own sector and began to withhold tithes to the Imperium, Terra seemed to care little for centuries.

Viewed together, these elements seem to suggest that the Imperium actually tolerates (to a certain extent) chapters who haven't definitively proven their descent from a loyalist Legion, simply because it can't spare a single Chapter in the fight for its continued survival.

 

I will however nuance this opinion slightly by saying that, when writing your own DIY, you should never outright state that your Chapter is descended from a traitor Legion: since Indices Astartes and similar Chapter descriptions are written from a semi-in-universe point of view, outright telling your reader that your new DIY is descended from a traitor Legion gives the impression that this is in-universe knowledge, and it seems to me that the Imperium would no longer be able to tolerate such a state of affairs; all they can tolerate is a certain amount of doubt.

Instead, take inspiration from the aforementioned Chapters, like the Minotaurs, Carcharadons, Silver Skulls and Blood Ravens: Games Workshop, Forge World and Black Library publications go to great lengths to enfuse a certain atmosphere of mystery, for instance by presenting a number of conflicting in-universe theories about their true nature, but never stepping too far one way or the other. Sometimes, a supposed parent legion is given, other times there is no clue; either way, the crumbling monolith that is the Imperium doesn't seem to really care, just as long as the Chapter keeps fighting in its name.

 

 

Regarding the possibility of a Lost Legion:

first of all, you need to consider what era you want to be working in - if you want to create a DIY that has its events happening during the Great Crusade, that's fine, have a blast; if you want to create a Chapter for the 41st Millenium? That's going to be singularly more complicated, as both lost Legions seem to have been destroyed so thoroughly that even their names are gone - making any suggestion that survivors of one of these legions could have given rise to a separate chapter in the years following the Horus Heresy would be a far more extraordinary claim and therefore more difficult for the average reader to accept. In the latter case, nothing's stopping you from doing it anyway, but in that case I'd advise you to follow the same advice as I made in the previous section: don't make any outright claims, sprinkle a few elements pointing towards what your own vision for them is, but sprinkle just as many elements pointing in completely opposite directions.

 

However, I'd like to warn you of one thing when creating a Lost Legion: whilst a DIY Chapter should be unique in nature, it is one of a thousand other Chapters, which all have relatively similar sizes and organisations and combat styles that often (but not always!) ressemble those of their parent Legion - as such, they actually have a fairly rigid structure already in place. When regarding one of the Lost Legions, you have to create a culture and tactical preference that is different from the other 18 legions, making it unique enough to be one of only 20 - basically, you need to think of how to have a new stereotype. If the "Silent Hunters" are as close tactically and aesthetically to the Raven Guard and Night Lords as your poll suggests, I find I have to question how you'd make them unique enough to be their own stereotype.

On top of that, you should also consider what on earth this Legion could have done that was so bad that it merited their complete erasure from history, a fate that even nine Legions rising in direct rebellion in the name of the Dark Gods didn't deserve.

 

 

 

TLDR: Do what you want, just hide the info in half and false truths. Also, don't focus too much on their ancestors: instead, focus on what makes them them. :)

[Bjorn Firewalker]

Well said, Lord Thorn.

[Naoki the curseblood 99]

Okey dokey, sorry to have missed this for so long, but I'll try and give my view:

I think that a potential successor of a chaos legion is entirely feasible.

 

Until last year, I'd have probably agreed with Bjorn on how little doubt the Imperium is inclined to allow before destroying a chapter of dubious descent (and therefore in their minds, loyalty).

However, the Gathering Storm and 8th edition fluff has shed a certain amount of light on just how dire the situation of the Imperium is - until now, it had always seemed that the monolithic might of the galaxy, while beset on all sides, was pretty much standing strong, and only the advent of new threats (tyranids, necron, tau, 13th black crusade etc.) were starting to make the ship rock. In fact, with storylines like the Beast Arises and the Black Legion trilogy, we have seen how frail the Imperium truly is, right from the closing days of the Scouring. The events of the Gathering Storm would have been enough to topple the whole edifice, if it weren't for the rebirth of a Primarch.

In light of this, we look again at how other chapters of dubious origin have been treated in the past: the Carcharadons for instance are greeted by loyalist chapters after their exile millenia long with mistrust, yes, but aren't actively persecuted; the Minotaurs (whose geneseed is not only suspect, it was given them during the Cursed Founding) have been to war with loyal chapters and disappeared from Imperial records for some time, and yet they were not hunted down either; the Silver Skulls and Blood Ravens have elements in their nature and history suggesting they could be of Traitorous descent, and yet the Imperium never seems to look too closely at their past; even in the case of the Badab War, when Huron appointed himself the leader of his own sector and began to withhold tithes to the Imperium, Terra seemed to care little for centuries.

Viewed together, these elements seem to suggest that the Imperium actually tolerates (to a certain extent) chapters who haven't definitively proven their descent from a loyalist Legion, simply because it can't spare a single Chapter in the fight for its continued survival.

 

I will however nuance this opinion slightly by saying that, when writing your own DIY, you should never outright state that your Chapter is descended from a traitor Legion: since Indices Astartes and similar Chapter descriptions are written from a semi-in-universe point of view, outright telling your reader that your new DIY is descended from a traitor Legion gives the impression that this is in-universe knowledge, and it seems to me that the Imperium would no longer be able to tolerate such a state of affairs; all they can tolerate is a certain amount of doubt.

Instead, take inspiration from the aforementioned Chapters, like the Minotaurs, Carcharadons, Silver Skulls and Blood Ravens: Games Workshop, Forge World and Black Library publications go to great lengths to enfuse a certain atmosphere of mystery, for instance by presenting a number of conflicting in-universe theories about their true nature, but never stepping too far one way or the other. Sometimes, a supposed parent legion is given, other times there is no clue; either way, the crumbling monolith that is the Imperium doesn't seem to really care, just as long as the Chapter keeps fighting in its name.

 

 

Regarding the possibility of a Lost Legion:

first of all, you need to consider what era you want to be working in - if you want to create a DIY that has its events happening during the Great Crusade, that's fine, have a blast; if you want to create a Chapter for the 41st Millenium? That's going to be singularly more complicated, as both lost Legions seem to have been destroyed so thoroughly that even their names are gone - making any suggestion that survivors of one of these legions could have given rise to a separate chapter in the years following the Horus Heresy would be a far more extraordinary claim and therefore more difficult for the average reader to accept. In the latter case, nothing's stopping you from doing it anyway, but in that case I'd advise you to follow the same advice as I made in the previous section: don't make any outright claims, sprinkle a few elements pointing towards what your own vision for them is, but sprinkle just as many elements pointing in completely opposite directions.

 

However, I'd like to warn you of one thing when creating a Lost Legion: whilst a DIY Chapter should be unique in nature, it is one of a thousand other Chapters, which all have relatively similar sizes and organisations and combat styles that often (but not always!) ressemble those of their parent Legion - as such, they actually have a fairly rigid structure already in place. When regarding one of the Lost Legions, you have to create a culture and tactical preference that is different from the other 18 legions, making it unique enough to be one of only 20 - basically, you need to think of how to have a new stereotype. If the "Silent Hunters" are as close tactically and aesthetically to the Raven Guard and Night Lords as your poll suggests, I find I have to question how you'd make them unique enough to be their own stereotype.

On top of that, you should also consider what on earth this Legion could have done that was so bad that it merited their complete erasure from history, a fate that even nine Legions rising in direct rebellion in the name of the Dark Gods didn't deserve.

 

 

 

TLDR: Do what you want, just hide the info in half and false truths. Also, don't focus too much on their ancestors: instead, focus on what makes them them.

I see your point but I may require assistance with making it like this I'll try to write them as a lost legion as that could prove interesting but I am but I'll have to move them to the liber chaotica if I am to do this but is it  necessary to use the standard legion organization or could be altered in a way akin to a non codex compliant  chapter?

[Bjorn Firewalker]

If you make the Silent Hunters a "Lost Legion," i.e., II or XI Legion, you risk having other readers denounce your Marines as canon-violating Mary Sues. As for being Codex noncompliant, you need good reasons to justify such behavior among loyalist Marines, as noncompliance with the Codex will automatically make other Imperial institutions suspicious. Not even the Space Wolves- the Emperor's executioners, trusted with the impossible tasks of eliminating the II and XI Legions- were above suspicion after the Heresy! (Chaos Marines, understandably, don't give a damn about Codex compliance- not that they can, as they must do without many resources and contacts a loyalist Chapter enjoys.)

[Naoki the curseblood 99]

If you make the Silent Hunters a "Lost Legion," i.e., II or XI Legion, you risk having other readers denounce your Marines as canon-violating Mary Sues. As for being Codex noncompliant, you need good reasons to justify such behavior among loyalist Marines, as noncompliance with the Codex will automatically make other Imperial institutions suspicious. Not even the Space Wolves- the Emperor's executioners, trusted with the impossible tasks of eliminating the II and XI Legions- were above suspicion after the Heresy! (Chaos Marines, understandably, don't give a damn about Codex compliance- not that they can, as they must do without many resources and contacts a loyalist Chapter enjoys.)

i see your point

Well i may have a idea for the allegiance of the chapter perhaps the former legion are basically hunters for hire hunting down the most dangerous foes

My idea for this legions organization is that they strongly believe in quality over quantity to the point that the only units that work in squads are the neophytes

[Minigiant]

Now if you are happy to have "Mary Sue" marines then ignore the following advice

 

It seems you are trying to change everything. You have lost legion, works as individuals. One of those traits is hard enough to make feasible and believable, both seems daunting and a little too jarring.

 

Your enthusiasm is great but I do highly suggest filing away all the 'noise' and finding that core idea that you want.

 

To me it sounds like you want a Deathwatch style combat doctrine army with a mysterious past, now that is more than possible

[Naoki the curseblood 99]

Now if you are happy to have "Mary Sue" marines then ignore the following advice

 

It seems you are trying to change everything. You have lost legion, works as individuals. One of those traits is hard enough to make feasible and believable, both seems daunting and a little too jarring.

 

Your enthusiasm is great but I do highly suggest filing away all the 'noise' and finding that core idea that you want.

 

 

To me it sounds like you want a Deathwatch style combat doctrine army with a mysterious past, now that is more than possible

my sincere apologies i do not intend for them to be these perfect marines they'll have several flaws with a higher gene seed rejection rate and a malfunctioning black carapace but i see your point you're right that i would like them to opperate as independent opperatives but i lack the knowledge to make a legion so I'll have to settle with a different idea but i will say this you've done great work on your chapter for that you have my respect Edited February 19, 2018 by Naoki the curseblood 99

[Bjorn Firewalker]

my sincere apologies i do not intend for them to be these perfect marines they'll have several flaws with a higher gene seed rejection rate and a malfunctioning black carapace but i see your point you're right that i would like them to opperate as independent opperatives but i lack the knowledge to make a legion so I'll have to settle with a different idea but i will say this you've done great work on your chapter for that you have my respect

Imperfection does not make a character less of a Mary Sue. (For comparison, go to any website where Rey, from 'Star Wars: The Force Awakens' and 'The Last Jedi', is discussed.) Plausibility of a character from a certain background, having certain abilities, and being viewed favorably by people from different backgrounds, WILL.

 

Omit the "higher gene-seed rejection rate and a malfunctioning black carapace"- the latter will prevent the Marines from effectively using power and Terminator armor, and seems as pointless a "flaw" as Rey's lack of resistance to the Dark Side of the Force. Just focus on writing a Chapter origin, history, and future plans- what goals your Marines intend to accomplish- that are plausible to us readers, as well as to other characters in the 'Warhammer 40,000' universe.

[Minigiant]

 

my sincere apologies i do not intend for them to be these perfect marines they'll have several flaws with a higher gene seed rejection rate and a malfunctioning black carapace but i see your point you're right that i would like them to opperate as independent opperatives but i lack the knowledge to make a legion so I'll have to settle with a different idea but i will say this you've done great work on your chapter for that you have my respect

 

 

I think I agree with Bjorn, those flaws are a little 'meh' and have no real baring on the chapters personality

 

Flaws are what define a chapter they dont always have to be genetic (but those are easier I think), they can be personality trait, look at Imperial Fists.

 

They are called SILENT HUNTERS why not give them a mutation that removes their voicebox. They can still communicate through written commands and sign language but, it would make them be more self sufficent in combat.

 

It would make lots of interesting diversions in practice. How do they recruit? They would have to steal recruits because it would be difficult to persuade people to join them being unable to speak.

 

Organisation, you would probably need more links to command

 

Why do they have that mutation? You can tie it into a mysterious backstory. You can even give the chapter their name from what people referred to them as because they couldnt exactly tell people their chapter name. So you have  chapter referred to as the Silent Hunters because that is what they are but, their true name is unknown

 

Just an idea. If you read through my entire chapter thread you can follow my emotional rollercoaster. It takes time

 

It is easier to grow a single tree from one seed than from many. Choose your seed and go from there

Edited February 19, 2018 by Minigiant

[Bjorn Firewalker]

They are called SILENT HUNTERS why not give them a mutation that removes their voicebox.

Better to just have the Marines take a Vow of Silence when they're promoted from the rank of Scout or Neophyte. Why?

 

Silent Hunters Scout: "According to the First Chapter Master's journal, he spoke of a secret that should never have been revealed. Because of his mistake, billions died, and the First Chapter Master's honor was forever lost. In penance, the First Chapter Master took a Vow of Silence, and all his successors must take the vow in turn, so we will not speak of that which should not be spoken- at least that's what the Sergeant allows me to say. Who's our First Chapter Master? I'm not allowed to say his name."

 

That should give your Chapter the degree of mystery you seek.

Edited February 19, 2018 by Bjorn Firewalker

[Naoki the curseblood 99]

 

my sincere apologies i do not intend for them to be these perfect marines they'll have several flaws with a higher gene seed rejection rate and a malfunctioning black carapace but i see your point you're right that i would like them to opperate as independent opperatives but i lack the knowledge to make a legion so I'll have to settle with a different idea but i will say this you've done great work on your chapter for that you have my respect

 

 

I think I agree with Bjorn, those flaws are a little 'meh' and have no real baring on the chapters personality

 

Flaws are what define a chapter they dont always have to be genetic (but those are easier I think), they can be personality trait, look at Imperial Fists.

 

They are called SILENT HUNTERS why not give them a mutation that removes their voicebox. They can still communicate through written commands and sign language but, it would make them be more self sufficent in combat.

 

It would make lots of interesting diversions in practice. How do they recruit? They would have to steal recruits because it would be difficult to persuade people to join them being unable to speak.

 

Organisation, you would probably need more links to command

 

Why do they have that mutation? You can tie it into a mysterious backstory. You can even give the chapter their name from what people referred to them as because they couldnt exactly tell people their chapter name. So you have  chapter referred to as the Silent Hunters because that is what they are but, their true name is unknown

 

Just an idea. If you read through my entire chapter thread you can follow my emotional rollercoaster. It takes time

 

It is easier to grow a single tree from one seed than from many. Choose your seed and go from there

  

Bettervto just have the Marines take a Vow of Silence when they're promoted from the rank of Scout or Neophyte. Why?

Silent Hunters Scout: "According to the First Chapter Master's journal, he spoke of a secret that should never have been revealed. Because of his mistake, billions died, and the First Chapter Master's honor was forever lost. In penance, the First Chapter Master took a Vow of Silence, and all his successors must take the vow in turn, so we will not speak of that which should not be spoken- at least that's what the Sergeant allows me to say. Who's our First Chapter Master? I'm not allowed to say his name."

That should give your Chapter the degree of mystery you seek.

i see I'll probably go with a mutation as you suggested i have an idea where the chapter was created during the 21st founding at the request of a radical lord inquisitor

[Doctor Perils]

I see your point but I may require assistance with making it like this I'll try to write them as a lost legion as that could prove interesting but I am but I'll have to move them to the liber chaotica if I am to do this but is it necessary to use the standard legion organization or could be altered in a way akin to a non codex compliant chapter?

Hum, I'd argue that you could write a lost legion here in Liber Astartes.

However, I'd still heavily advise against writing them as one.

a - as Bjorn and Minigiant suggest, this will raise many a readers' defenses against your chapter. Ultimately, that has little bearing because you are writing this primarily for your enjoyment, not other peoples', but even then it's more enjoyable for you if other people enjoy what you write too :)

b - Even considering your idea of making them essentially mercenaries, I'm not sure how different they would be from other legions - in particular I'm getting an Alpha Legion feel from them at the moment.

c - The Lost Legions are Lost. That is an established fact, one of the few in the 40k universe. Whether the Legionnaries are all dead or whether they were taken in by the Ultramarines or any of the other options in between, no-one in-universe will believe someone who claims they descend from the II/XI. As such, it won't actually add anything to the index, and may in fact retract from it, as per reason a -.

---> a caveat exists for this however : if you wish only to create your version of the IInd legion, from their creation, to their destruction, all the way through the discovery of their Primarch and the Great Crusade, that's fine in itself ; however, youll have your work cut out to not be seen as yet another raven guard/night lords/alpha legion.

 

 

I fear however that we're looking at this from the wrong end - do not focus at all on the chapter's provenance in the first place. Instead, tell us how they function today (if today is 40k or 30k also, as that will mean a big difference). Why do they function like that? What is their goal? Where do they come from? How do they fight? What are their beliefs? -> those are more important to establish in the first place, and only then you can look at whether you even want to explore their ancestors in the first place (something that Games workshop seems to rarely do)

[Naoki the curseblood 99]

 

I see your point but I may require assistance with making it like this I'll try to write them as a lost legion as that could prove interesting but I am but I'll have to move them to the liber chaotica if I am to do this but is it necessary to use the standard legion organization or could be altered in a way akin to a non codex compliant chapter?

Hum, I'd argue that you could write a lost legion here in Liber Astartes.

However, I'd still heavily advise against writing them as one.

a - as Bjorn and Minigiant suggest, this will raise many a readers' defenses against your chapter. Ultimately, that has little bearing because you are writing this primarily for your enjoyment, not other peoples', but even then it's more enjoyable for you if other people enjoy what you write too :)

b - Even considering your idea of making them essentially mercenaries, I'm not sure how different they would be from other legions - in particular I'm getting an Alpha Legion feel from them at the moment.

c - The Lost Legions are Lost. That is an established fact, one of the few in the 40k universe. Whether the Legionnaries are all dead or whether they were taken in by the Ultramarines or any of the other options in between, no-one in-universe will believe someone who claims they descend from the II/XI. As such, it won't actually add anything to the index, and may in fact retract from it, as per reason a -.

---> a caveat exists for this however : if you wish only to create your version of the IInd legion, from their creation, to their destruction, all the way through the discovery of their Primarch and the Great Crusade, that's fine in itself ; however, youll have your work cut out to not be seen as yet another raven guard/night lords/alpha legion.

I fear however that we're looking at this from the wrong end - do not focus at all on the chapter's provenance in the first place. Instead, tell us how they function today (if today is 40k or 30k also, as that will mean a big difference). Why do they function like that? What is their goal? Where do they come from? How do they fight? What are their beliefs? -> those are more important to establish in the first place, and only then you can look at whether you even want to explore their ancestors in the first place (something that Games workshop seems to rarely do)

i see your point but is it a mary sue like idea to have a chapter recruit a stable race of abhuman?