Onslaught

A persistent enchantment that converts every creature you play into a small tempo tax on an opponent's board, reading the act of casting a creature spell as the trigger rather than the creature itself entering. That distinction is the whole design: the tap happens off the cast, not the resolution, so a counterspell or removal aimed at the creature does not stop the tap from landing, and creatures with cast-based effects of their own stack neatly on top. The natural home is a deck that floods the board with cheap bodies, where each one doubles as a single-target Twiddle pointed at the biggest blocker or the next attacker you want kept on its back foot. It is a slow-burn engine more than a swing: one mana up front, then a steady drip of taps that smooths attacks and disrupts blocks without ever generating a creature or a card on its own. What bounds it is its appetite for volume; with no creature spells to cast, the enchantment sits there doing nothing, and even with a steady stream it never threatens to lock a board down the way a repeatable tapper attached to a body might. Onslaught is a build-around for go-wide red, the kind of cast-trigger payoff that rewards committing to a low curve rather than offering value in any deck that happens to run it.