Pichi, Merfolk of the Deep

Islandwalk
When you cast an instant or a sorcery spell
place a +1/+1 counter on Pichi, Merfolk of the Deep.
Remove two +1/+1 counter on Pichi, Merfolk of the Deep {t}: Search your deck for a Merfolk creature, reveal it and shuffle your deck.
Place the revealed card on top.