So the WH40k universe is filled with weapons that have become relics, because they killed 1000s of xenos or demons.
Maybe fusion is the...background reason for that, and if so, that's fine. But it would be neat to have cabal relics or gear with a reputation outside the wielder. Relics are great. But...right now at least, they're really generic and...it's harder to say InquisitorX's powersword with the +cr +cd +vuln +ork slaying is so cool, versus...he wields orc reaper...
I will try really hard to stop now. No promises.