The Avenging Lions chapter sends battle-brothers to the Legio [Bolter & Chainsword]. One of the battle-brothers that has been seconded to the Legio over the millennia of the chapter's existence was Brule Onathemes, known as the Spear-Slayer.

Brule Onathemes

Pict capture in 709.M39 upon secondment to the Legio Bolter & Chainsword

Formerly a battle-brother of the 3rd Tactical Squad, 5th Company, Brule was awarded the Imperial Laurel for his valor during the Jurekai Punitive Expedition. He has sworn his oath upon his sword of justice. Brule was seconded to the Legio Bolter & Chainsword in 709.M39 and served in the Justice of the Emperor Great Company.

In keeping with the traditions of the Legio, Brule recorded his deeds on an honor shield. Upon his death, the record on his honor shield was duplicated onto two death shields, one of which covered his sarcophagus for return to the Avenging Lions and the other hung with his honor shield in the Legio's Hall of Heroes as a memorial.

Notes

This was an interesting diversion, and one of the few developments I ever got around to for the Avenging Lions. One day I hope to get that Legio mini-me converted and painted. It will be a firstborn Space Marine since I have locked the character into a pre-Primaris time period, but I may create a Primaris battle-brother from the Avenging Lions later.

The outline of the shield has a slight red border, and that was much worse in the template that was provided. While I deleted the most egregious red bits, some of still remains (and rankles me - I may have to fix that one day).

The lion and eagle imagery comes from an old poster, America's Tribute to Britain, by Frederick G. Cooper in 1917 and published by the Marchbanks Press, New York. It is used without permission and has been Photoshopped to be different from the actual image (blurring the lines, using a different background color, slight cropping). I was originally going to use a lion in the style of the Finnish army, but this one caught my eye as being cool, distinctive, and a lot more obscure than the former.

The chapter icon features at the top center.

Brule's name appears on the silver name plate on the left, along with a black tactical squad badge and the number 3 in white, indicating his original squad affiliation.

On the right you can see a stylized rendition of Brule's oath-blade (described in the chapter article) along with the text of the oath he swore upon being seconded to the Legio.

I imagine that Brule added to the decorations upon the shield during his time in the Legio, that the version shown above was simply how the shield appeared upon the initiation of his secondment.