A world beyond the bounds of Mavor, but sickeningly close to it. Gharus XI is, in essence, Chaos’ version of an Imperial Prison World — where millions work menially, suffer, and are held captive until the moment of their deaths, and sometimes beyond. Its vast furnace-pits burn night and day, while screams of the tortured rise with their towering flames to its steel-gray sky. The products of this fell industry go on to feed the war machine of many warbands and cults in the Eastern Fringe, with the pale, grim-faced Dark Mechanicum slave-masters of Gharus taking great pride in serving the World Devastators, the Haunted Spectres, the Tizcan Flame, and others still. 
 

Tarn of the World Devastators, in particular, enjoys a close relationship with the Gharusian Mechanicum. Many times, he has ‘dropped off’ a particularly vexatious foe as a prisoner there, to work until they die. Only few have ever escaped from Gharus, and they are never the same afterwards. Among these escapees are Tarn’s perennial foe Godwyn Bullroarer, and the Eldar Outcast, Niall. 

-From the records of Bede of New Albia, Savant-Acolyte to Inquisitor-Lady Vreiken

 

"It's either you or me! There can only be one, Eldar!"
 

"NO! Put that weapon down, Space Marine - child of Terra! Listen to me. We have need of each other. On Gharus, we are all brothers in chains. The hand or the weapon, Space Marine - choose!"
 

"I - Ferdiad - The Cors - Father - Uncle - Tarn - I..."

"That's it. You've chosen. This is no trick, brother."
-The sword-meeting of Niall Way-Leaver and Godwyn Bullroarer, in the fighting pits of Gharus XI. 
 

——— ——— ———

The coda to our little story: Niall, after his stay on and escape from the Chaos Prison World of Gharus XI. There, he met Godwyn Bullroarer of the Greymanes Chapter, and with their fellow prisoners, they concocted an escape plan. However, the victory was not clean. Many of their fellow prisoners died in the escape. 

For Niall's sake, Godwyn parted from him, not particularly keen to have the wrath of the Imperium fall upon one who had so helped him. Niall now once more wanders Mavor, aimless, unsure of himself and his allies...

This will be a Ilic Nightspear proxy, assuming he's around by codex drop. If not, I will replace the base.