The River of Oblivion

At the beggining of yor turn, put a -1/-1 counter
on all creatures and put an oblivion counter on
The River of Oblivion.
Remove all oblivion counters from The River
of Oblivion: Exile target non-land permanent
with a converted mana cost of {x} or less. You lose {x} life.
{t}, pay 2 life: Add {c}{c}.