Arnuim, the Frosted Petal

Haste
When Arnuim, the Frosted Petal enters the battlefield, look at the top six cards of your library. You may reveal a land and/or legendary
permanent card from among them and put it into your hand. Put the rest on the bottom of your library in any order.
Whenever you cast a legendary spell, put a +1/+1 counter on Arnuim.