>>43251620The Laniatus Blade.
A two handed, lathe-forged, power great-sword made of a single shaped and carved slab of depleted deuterium. (the shit they use for the very tip of bolt shells) (Yes I know it's magic water irl, GW is dumb)
Crafted in the heart of a dying plasma reactor by a forge-saint, made a masterwork, scrimshawed, and fine tuned by the that same Forge-Saint.
Gifted to the Deathwatch, it saw thousands of years of service before needing to be repaired.
It's repair made it function additionally as a psy-focus and psy-blade.
They bound the soul of a primaris-level pyromancer psyker to the blade so it forever burns a low simmer of white flame, a power that can be flared with the assistance of the wielder's psy rating.
A strike from this blade results in more than cutting the flesh, it burns the very soul with holocaust-warpfire not only killing them but permanently destroying their souls.
The blade's esoteric runes, carvings and enchantments then soul-syphon the now dissipated soul-energy and warp-essence into the blade, fueling it and temporarily increasing it's power.
Additionally the handle was modified with nano-quicksilver, shaping itself to the hand of the wielder, making every use of the blade feel as though it were crafted for their hands alone.
Also a scum character put his lucky dice (memento, lucky item and keepsake in one item) on the pommel.