Draugr Necromancer

Theft effects usually take one creature and stop there; this one rewrites your opponent's death step into a slow-building larder that only grows as the game drags on. Because the first ability is a replacement effect (their nontoken creatures never reach the graveyard at all, but land in exile under an ice counter instead), it attacks two resources at once: it denies them their own reanimation and creature-recursion targets, since the bodies never touch the yard, and it simultaneously hands you a stockpile of spells to cast. The clause that makes the whole thing work outside mono-black is the snow-mana-as-any-color permission: normally a stolen green or white bomb sits uncastable behind a color barrier, but here your snow sources pay for whatever those cards demand, so an opponent's payoffs become yours to deploy off untapped snow lands. What holds the whole thing in check is the narrowness of the replacement itself. It applies only to nontoken creatures, and only when one would actually die, so decks that bounce, blink, exile their own bodies, or simply refuse to trade sidestep it entirely, and even a full exile pile is inert until you spend real mana casting what you have accrued. Left running across a grinding game, though, it inverts attrition: every board wipe and chump block your opponent survives quietly funds the pile that eventually buries them.