Alternate timeline (The Book of the War)
Faction Paradox claimed that their iconic ceremonial armour was made from the bones of vampirised Homeworlders from an alternate timeline where the Yssgaroth won the war and corrupted their fallen enemies. However, the Houses denied this claim (in line with their insistence that alternate timelines didn't exist), and even Faction experts on the Yssgaroth thought there may be more to the story. At any rate, the bones were sourced from an "abomination's graveyard" accessed by the Godfather-lieutenants of the Grandfather through the caldera. (PROSE: The Book of the War)
At Qixotl's auction, Justine and Manjuele wore larger-than-human horned skulls from Time Lords of this timeline, leading Homunculette to annoyedly remark, "even their headgear breaks the Laws of Time." Justine noted that such a history would be caused "by the grace of Time". (PROSE: Alien Bodies)