Cosmic Rebirth

The instant-speed clause is the whole trick here. Green-white recursion has traditionally been sorcery-speed, tied to bodies you replay on your own turn: Sun Titan, Reveillark, the Regrowth family. This one flashes back a permanent card at the end of an opponent's turn, in response to a removal spell, or mid-combat to rebuild before your own attack, and it does so with a branch that reads the graveyard's contents rather than forcing a single mode. A cheap creature, artifact, enchantment, or land comes straight to the battlefield; anything above the mana-value line falls back to your hand instead, so the spell never bricks on a target it cannot cheat out. That flexibility is the design work: pure reanimation-to-play would be too strong on the high end, pure return-to-hand too weak on the low, and splitting the outcome by cost lets one card cover both without a mode you have to pick before you know the graveyard. The three life is the small tax-offset that keeps a value instant honest in a color pair that already grinds. What it recovers most naturally is the mana dork or utility land you lost, or a land drop you skipped, folding graveyard recursion, a land-return safety valve, and lifegain into a single blink of instant-speed insurance.