Acheron, Nihility's Shadow

Whenever a card is exiled give it a Slashed Dream counter.

Whenever Acheron, Nihility's Shadow deals combat damage to a creature, exile it.

When Acheron, Nihility's Shadow attacks or blocks exile target permanent you control.

If there are 9 or more Slashed Dream counters, you may discard your hand or pay half your life rounded up to transform Acheron, Nihility's Shadow.