Door to the Dragon Prison

Search your library for a dragon creature card with converted mana cost X or less, where X is the number of dragons you control. Reveal it, and put it onto the battlefield. It gains "This creature attacks every turn if able." and "Your devotion to red is twenty."
"This we swear to you: when this barrier falls, we will make you know what true suffering is."
-Veshnur Dragon King, last words