Daan, the hopeful

Whenever Daan, the hopeful attacks, bolster 1.
(Choose a creature with the least toughness among creatures you control and put a +1/+1 counter on it.)
Whenever Daan, the hopeful blocks or is blocked,
exile Daan, the hopeful. Return it to the
battlefield under its owner's control at the
beginning of the next end step, then proliferate.
"I, Daan, have a piano."