Explosive Singularity

Ten damage is the number that ends any game outright: it clears the biggest threats, kills through most incidental lifegain, and turns a topdeck into a concession. The trick is the price. At ten mana this is a spell you cast on turn ten or never, so the tap-based rebate reframes the whole thing as a payoff for a wide board rather than a ramp payoff. A go-wide red deck that has already committed its threats to the table can convert those bodies, briefly, into a discount: tap six creatures and the spell suddenly costs four, arriving on a turn where the board was going to attack anyway. That is the tension the design resolves. A creature-light deck pays full freight and rarely gets there; a deck flooded with untapped bodies gets to fire it early, but only by declining to attack with the very creatures it taps, since tapping for the additional cost pulls them out of the combat step. The spell rewards the exact board state (many small creatures, all of them idle for a turn) that a purely aggressive plan usually wants deployed elsewhere. It is a haymaker built for the moment the ground stall has already formed and the attack step no longer matters, when the choice becomes whether to swing for incremental damage or tap the whole team to deliver ten to a face in one shot.