Firespout

Most sweepers ask one question: how big is the board you want gone. This one asks a second question first, and it asks it through the mana you tap. Spend red and the ground burns; spend green and the air does; spend both and the whole battlefield takes three. The routing tracks the color pie exactly rather than bending it: red has always been the color of ground-clearing burn that leaves fliers untouched, and green has always been the game's primary answer to the sky. What makes the card unusual is not the division of labor but that it hands a single spell both halves and lets the pilot select which one fires at the moment of casting, scaling the blast radius to the matchup without committing heavy mana to do it. The catch is that the damage is fully symmetrical, hitting your own creatures as hard as the opponent's, so the spell favors boards built to outlive it: anything with four toughness survives, anything airborne lives when you pay only red, anything you mean to keep stays out of range if you pay carefully. That self-inflicted half is the price of a sweeper this cheap. The flexibility and the friction live in the same hybrid pip, which is what lets the card serve as a genuine green answer and a genuine red one at once instead of a compromise that handles neither job well.