Khanun, Ryukyu's Fury

Cumulative upkeep — Sacrifice a creature.
When Khanun, Ryukyu's Fury enters the battlefield, creatures lose flying and can't gain
flying until end of turn.
{x}{g}{u}: Creatures without flying get -X/-X until
end of turn.
When Khanun leaves the battlefield, each player sacrifices a creature they control.