Maelstrom Muse

The reduction scales with power, and the timing on that clause is the whole design. The ability doesn't lock in a discount when you declare the attack; it reads power as the trigger resolves, which means any pump effect you slip in between combat and resolution grows the discount along with it. A 2/4 flier baseline shaves two off your next instant or sorcery, but a well-placed combat trick or anthem turns that into a genuine burst of free mana on the same spell. What that timing rewards is an awkward inversion of how spell-heavy decks want to play: attack first, cast second, all inside one turn. Most Izzet builds would rather commit nothing to the red zone and hold up interaction, so this asks you to send an evasive body into damage before you know what the turn will look like, then convert the attack into a discounted double-spell turn or an oversized X spell. The hybrid pip keeps it castable from a build leaning either color, but the payoff never shows up passively; it only exists when you're willing to swing and then spend. A static cost reducer sits back collecting value on its own terms, whereas this one earns nothing until you commit to combat, so it wants a shell built to attack and cast in the same breath rather than one that parks a threat on the battlefield and waits.