Walk the Plank

Doom Blade with a flavor tax. Black's two-mana "destroy target creature" has always carried a rider to keep it from being unconditional: Doom Blade walls off black creatures, Go for the Throat spares artifact creatures, Ultimate Price hits only monocolored bodies. The exclusion here is a tribe, not a color or a type, and that choice is doing two jobs at once. Mechanically, the Merfolk clause is a thin restriction that almost never bites in practice, since you rarely point a kill spell at the one tribe it can't touch. But it also rewrites the cost line: this is double-black removal at sorcery speed, which is the real price you pay for an effect that reads as nearly unconditional. The color intensity locks it to mono-black or heavily black decks, and the sorcery timing strips out the instant-speed flexibility that makes Go for the Throat the default. What you get in exchange is permanence and breadth: it kills indestructible-less creatures of any size, any color, any type, with none of the "nonblack" or "nonartifact" carve-outs that the instant-speed two-drops lean on. The Merfolk text is the flavor seam holding it to its world of origin, but underneath it's a study in how black removal trades timing and color commitment for the cleanest possible kill clause.