Arceus, Almighty Sinnoh

Whenever you cast a white spell, put a +1/+1 counter on each legendary creature you control.
They gain vigilance until end of turn.

Whenever you cast a black spell, put a +1/+1 counter on each legendary creature you control.
They gain menace until end of turn.

It is said to have emerged from an egg in a place where there was nothing, then shaped the world.