Eziar The Destructive

Flying,Firststrike,Haste
when you cast Eziar The Destructive choose Khans or Dragons.
.Khans-whenever a dragon enters the battlefield if you control 10 or more mountains it gains haste until the end of turn.
.Dragons-at the beginning of your upkeep reveal the top card of your library any opponent my choose to put that card in the graveyard if they do the take damage equal to its mana cost if not put it into your hand.