Soloriel, shadow trickster.

When Soloriel, shadow trickster
enters the battlefield invoke a creature with deathtouch (search your library for a creature with deathtouch, put it on the battlefield, then shuffle it back
into your deck)
Whenever a creature enters the battlefield, create a
1/2 black faerie dragon with defender, flying and
"At the beginning of your turn, this creature does damage
equal to it's power to another creature you control" under your opponents control.