Omnath, Locus of Mana

Green mana had always been ephemeral: ramp existed to be spent that turn, the burst of acceleration funding a creature or a spell before the phase ended and the pool emptied. This rewrites that contract. Mana floats turn to turn, accruing, and the body grows with the pile, so green's defining weakness (mana that cannot be banked) becomes a resource you stockpile like cards in hand. The design tension is what makes it sing and what makes it fragile. A 1/1 that does nothing unless you have already loaded a green reserve, it asks you to commit to a dangerous middle state: holding mana open, swinging with a creature whose size scales with your unspent fuel, betting that nobody removes it before you cash the pool into something explosive. Lose the creature and the floated mana is suddenly just mana, the threat gone with it. The interaction with mana-doublers is where the math turns combinatorial: every additional source of green compounds both the pool and the power, and a single untap effect on a large mana producer can dump the reserve into the body or a payoff in one motion. It sits in a small lineage of cards that treat unspent mana as something other than waste, but it is the one that turned the floated pool into a clock.