Dark Petition

Demonic Tutor for five mana reads like a downgrade until spell mastery reorganizes the math. The search itself is generic breadth: find any card, put it in hand, shuffle. What makes the rate work is the clause underneath it. If your graveyard already holds two or more instants and sorceries when this resolves, it adds . You pay five to cast it, then get three black mana back, so the net cost of the search lands at two, with black floating to fire off whatever you just fetched. That is the whole engine: instead of tapping out to tutor and stranding the payoff a turn behind, you chain the search directly into the thing it found. The timing rewards precision, though: spell mastery checks the graveyard as Dark Petition resolves, while the spell is still on the stack, so it never counts toward its own discount. You must arrive with the yard already stocked. Black tutors have always paid for their breadth somewhere. Demonic Tutor charges a flat two; Vampiric Tutor sells you a card on top of your library at a life cost; Diabolic Intent demands a creature. This one charges in deck identity, asking you to be the sort of build that buries spells in the graveyard, then refunding you for being exactly that. It is the rare tutor whose effective cost drops the longer the game runs, which makes it a midgame pivot rather than a curve-topper.