Exodia, Forbidden One

While this is in your command zone, you may
activate this ability as a sorcery once on your turns-
{4}{w}{u/b}{r/g}: You gain a Forbidden One counter.
This ability, and Exodia costs {1} less for each
Forbidden One counter you have.
Exodia is unaffected by all other cards.
When Exodia enters the battlefield, if you have
five Forbidden One counters, You Win The
Game.