They are the Legion of the Damned, supposedly the dying, gohstly remnants of the pre-Heresy chapter the Fire Hawks (Ultramarine descendants). Despite their appearance they are still loyal to the Emperor.
In pre-Heresy there were no "chapters", only Legions.
Though the Legions were organized on Chapters, but those were still considered to be part of the Legion. Do you mean something like that? An Ultramarine Legion Chapter?
Oops, yeah sorry I worded that very poorly, full disclosure I was kinda drunk when I wrote that, lol.
I think I meant something like 'the remnants of a successor (Fire Hawks) of a pre-Heresy legion (Ultramarines)'.
Fine work, love the shift from the smaller bone-work to the giant skull on his left pauldron (our right). The smoke-effects are also simply chefs-kiss.
look its obvious that they are imperial daemons of the big E. recent lore and books are practically saying so
but either way you did a beyond and above amazing job with this. its the most beautiful interpretation of LOD art I've ever seen
keep up the great work.