Consume Spirit

"Spend only black mana on X" is the line that pays for everything else. A drain effect that both burns and heals in equal measure rewrites a race the moment it resolves, so the design tax here is color purity: every point of damage and every point of life has to come from black sources, which fences the spell out of any deck that wants to splash a finisher and into builds that fund X off black symbols alone. That same clause was the balancing wheel on Drain Life back in Alpha, and this is the leaner take on the idea: identical dual-direction X effect, identical black-only funding, no spare text. The payoff is that the damage and the lifegain are always the same number, so one cast answers two questions at once: it removes a creature or burns out an opponent while pulling you back from the edge. In a color whose ramp comes from rituals and big land counts (Cabal Coffers, Nykthos, the whole Urborg engine), the black-only clause stops reading as a restriction and starts reading as a license to pour a heap of mana into a single hybrid kill-and-heal spell. It sits at the floor of black's tradition of converting surplus mana into a game-ending point of reach: the spell the color reaches for when it has more mana than it knows what to do with and needs that mana to do two jobs in one cast.