Nagorad's Vision

Whenever a Dragon enters the battlefield, put a Vision counter on Nagorad's Vision, and then deal
X damage to any target, where X is how many Vision counters there are on Nagorad's Vision.
{t}, remove 3 Vision counters from Nagorad's Vision: search your library for a Dragon, and
put it into your hand.
{t}, remove X Vision counters from Nagorad's Vision: search your library for a Dragon with
X or less converted mana cost, and then put it on the battlefield.