Sin-Bound Reki

If another creature you control was put into the graveyard or exile this turn, Sin-Bound Reki gets
+1/+1 until the end of turn.
{w}: Sin-Bound Reki gets Flying. At the beginning
of the next end step, exile Sin-Bound Reki.
"Perhaps this is what it means to be bound by sin. To
spin in the same circle, looking for where the sin lies,
and at some point losing sight of the way out."
—Renmei Communicator