Geth, Lord of the Vault

Most black reanimation pays a flat rate to drag one body back: this one bills you where X is the mana value of the target, so the price scales with the prize, and whatever arrives comes in tapped rather than swinging. The crucial restriction is whose yard it raids. This is not self-recursion; the ability reaches exclusively into an opponent's graveyard, which makes it a theft engine rather than a value loop on your own dead. The artifact clause widens the targets past creatures: a milled or destroyed equipment, mana rock, or colorless threat is just as live as a corpse, so anything an opponent has lost becomes harvestable. And the mill is not collateral. Each activation grinds the targeted player for X more cards, refilling the very supply you intend to plunder next turn. Left unanswered, that turns one opponent's library into a renewable pit you keep dipping into, the mill feeding the reanimation feeding the mill. The intimidate finishes the thought: a 5/5 that only artifact creatures or other black creatures can stop tends to land its hits, and against most boards it goes unblocked entirely. The whole package rewards patience over explosiveness; this is a slow, mana-hungry harvesting machine for the player content to keep paying installments to claim someone else's losses, not a one-turn payoff.