Emiel the Blessed

{3}: Exile another target creature you control,
then return it to the battlefield under its
owner's control.
Whenever another creature enter the
battlefield under you 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 whith either {g} or
{w}.)