Emiel the Blessed [Jumpstart]

3: Exile another target creature you control, then return it to the battlefield under its owner's control.
Whenever another creature enters the battlefield under your control, you may pay G/W. If you do, put a +1/+1 counter on it. If it's a Unicorn, put two +1/+1 counters on it instead. (G/W can be paid with either G or W.)