These weapons are ancient and barely understood artifacts. Xenos in origin, they ripple with a molecular realignment field that allows it to cleave through force fields and metaphysical wards easily. Speaking of the origins of these weapons is forbidden within the Deathwatch under penalty of excruciation.
It should be noted that whereas the 7th Edition Deathwatch codex states that the Xenophase Blade is of unknown origin, Duncan Rhodes, a miniature painter and web presenter for Games Workshop's Warhammer TV, says in a product review that this weapon is "a Necron weapon that they [the Deathwatch] turned back against the Aliens". This claim is not backed up by other official sources.
- 1: Codex: Deathwatch (7th Edition) — Armoury of the Deathwatch
- 2: Warhammer TV: Deathwatch - Building a Kill Team (published 22.08.2016) (last accessed 27 January 2020): 00h:07m:25s