Gaster, Forgotten Scientist

Phasing, Shroud
Gaster starts the game in exile.
At the beginning of your upkeep, remove a persistence counter from Gaster. If it has no persistence counters on it, exile it.
{4}{b}{b}{b}: If Gaster is in exile, put it on the battlefield and add a persistence counter to it.
{4}: Add a persistence counter to Gaster.