Blood Vassal

The body is the tax. Dark Ritual breaks even the moment it resolves; this Thrull spends three mana to hand back two, swallowing an entire turn before the arithmetic begins to favor you. What that purchase actually buys is deferral: two black mana parked as a 2/2 that can chump, trade, or stall until you need a sudden dark injection, then liquidates at instant speed. The timing window is the entire pitch. A ritual fires only when you cast it, locked to that one cast; a creature that produces nothing while it lives and converts to mana when it dies lets you bank the resource and spend it precisely when it matters, sliding an off-curve play into a late phase or fueling a sacrifice payoff after the body has already pulled combat duty. The Thrulls of this era ran on exactly this logic, bred to be expendable, their worth measured in what they became upon dying rather than anything they accomplished alive. A 2/2 is generous for the type, but there is no mistaking the design: a black creature built to be turned back into black mana, a delayed ritual disguised as a body so it can wait on the battlefield until the conversion finally pays off.