Riftwalker

Riftwalker enters the battlefield tapped. When
Riftwalker enters the battlefield, place all exiled
creatures from all players onto the battlefield
under your control. At the beginning of your
next upkeep exile all creatures under your control
except for Riftwalker, then create a 1/1 Green
and Black Hell Spawn creature token for each
creature exiled this way and place it onto the
battlefield under your control.
If Riftwalker were to be destroyed, exile it instead.
A man of great mystery, and