"Insane, you say? Good. Sanity is but the delusion that the universe follows rules of logic and reason; a belief held by fools and weaklings to protect their feeble minds from the unending terror they would experience were they to understand the truths of this universe. I need no such protection. And besides, Governor, what is more insane than to choose to be sane in a galaxy entirely lacking in sanity?"
―Kilbane's retort to being called insane by Governor Albin Harthumis of Erdax V.
Black Legionnaire Power Armor Built from the set of Mark VII Power Armor he wore as during his final days as Lahesael, all Imperial iconography was stripped from the armor, replaced with the colors and icons of the Sons of Horus, which themselves were later replaced with that of the Black Legion when Ezekyle Abaddon reorganized the Sons of Horus shortly after Kilbane's defection. No traces of Kilbane's former self remained on his armor, which he decorated with trophies taken from his most impressive kills. Most notable among these trophies was a holster for Kilbane's Bolt Pistol, carefully stitched out of human (specifically Astartes) skin.
Unholy Bolter & Bolt Pistol Much like Kilbane's power armor, his Bolter was the very same weapon he carried as the Dark Angel Lahesael. Originally a Mark IIIa Godwyn-pattern Boltgun, any holy Imperial symbols had long since been stripped from the weapon's casing, replaced with the terrible iconography of the Dark Gods. Much the same has been done with his Bolt Pistol, however, this weapon was not originally his, but rather was stripped from the mutilated corpse of a loyalist Space Marine whom was felled by Kilbane's sword.
Tainted Power Sword & Axe With the former forged within the darkest, most twisted depths of the Eye and the latter pried from the cold, dead hands of a Chaos Lord defeated in one-on-one combat, Kilbane's power weapons are fearsome instruments of death infused with the favor of the Dark Gods. Inscribed with unholy icons and blasphemous scripture, these weapons have spilt the blood of a thousand of the God-Emperor's champions.
Whether or not Kilbane truly qualifies as a Fallen Angel is a matter of some debate within the inner circle of the Unforgiven. While the fact that he fought on the side of The Lion during the fall of Caliban technically disqualifies him from being a Fallen Angel, the fact that Lahesael specifically connected his turn to Chaos with Luther and the other Fallen Angels complicates the matter significantly.