Gai-Mada, Powersiphoner

when Gai-Mada, Powersiphoner enters the battlefield you may pay {x} if you do creatures you control get +X/+X until end of turn
{x}{t} target creature gets -X/-X until end of turn and a creature you control gets +X/+X until end of turn
{u}{r}{g} create a 1/1 green wizard token with "{t} add {2} to your mana pool only spend this mana for {x} abilities