Frontier Siege

The split between Khans and Dragons is the whole design conceit: one mode is a ramp engine, the other is a fight package, and you commit to one as the enchantment resolves. Khans turns the card into a doubling ritual that fires twice a turn but only on your main phases, which means the green mana arrives precisely when you want to cast something and never when you'd want it for an instant. That phasing is what saves it from being a generic mana battery; it asks the deck to schedule big spells across two windows rather than hold up interaction. Dragons is the stranger half, a removal-flavored payoff that triggers off flyers entering and lets each one pick a fight on the way down. The mode never quite found its deck in its own era, partly because committing at resolution forces you to guess your game plan before you know how it develops, and partly because the fight clause wants a steady stream of flying bodies rather than one good one. What the card represents is a green attempt to bolt removal onto a permanent, using fight as the color-pie-legal way to kill things, while the Khans side hedges toward the color's more familiar job of making too much mana. Two genuinely different cards wearing one frame, and the choice you make is irreversible.