March of Otherworldly Light

White has always paid for its answers up front, in fixed mana, at a fixed rate, while black and blue get to defer or convert the cost. This design borrows the "March" cycle's exile-for-discount engine to solve that in a specifically white way: your surplus white cards become a mana rebate, so the same catch-all instant that costs seven against a big threat costs one or two if you are willing to feed it the dead cards clogging your hand. That gives white something it rarely has, a scalable answer that reaches an artifact, a creature, or an enchantment across the entire mana-value curve rather than living under a hard ceiling. The engine works because X is declared first and the reduction applies after: exiling cards pays down the total cost directly, so erasing an expensive permanent does not force you onto raw mana. Declare X at six, exile three white cards, and you are answering a threat for a single white pip. The additional cost is optional, which sets the floor honestly: with a thin hand it is simply an X-cost removal spell, and with a hand glutted on white it becomes near-free interaction for whatever slipped through. What makes the exile matter is that the fuel and the reach draw from the same resource, your hand, so every use is a live question of whether the cards you are burning are worth less than the permanent you are removing.