The Alkahest Powder in Remnant 2 is a crafting material that can be obtained after defeating an optional boss called Gwendil. This material allows you to craft a superior Weapon Mod called Witchfire.

I've been Googling this fake trailer-sort-of-thing all afternoon, trying to figure out whether it's a reference to a specific movie (other than Powder, of course) or just an insane pastiche of Powder ...