Shaman of Oblivion

Shaman of Oblivion has power equal to the
number of Soul Curse tokens on the field.
{b}{t} Attach one Curse of Oblivion token to
target creature.
{5} Exile Shaman of Oblivion. Destroy each
creature with a Curse of Oblivion token. If the
number of tokens on the field is 4 or greater,
exile them instead.