The Ur-Dragon (0361) [Commander Masters]

Legendary Creature — Dragon Avatar · {4}{W}{U}{B}{R}{G} · 10/10

Eminence — As long as The Ur-Dragon is in the command zone or on the battlefield, other Dragon spells you cast cost {1} less to cast.
Flying
Whenever one or more Dragons you control attack, draw that many cards, then you may put a permanent card from your hand onto the battlefield.

Commander Masters #361 · mythic · Art by Jaime Jones