Madelyn, Protector of Spirits

Flying, Hexproof
Madelyn's Power is equal to the number of
Spirits you control.
Other Spirits you control cost {1} less to cast.
Whenever a Spirit enters the battlefield under
your control, you may exile another target
creature with converted mana cost equal to or
less than Madelyn's power. If you do, draw half
that many cards, rounded up.