I actually used to have a jund ur-dragon list too, but took it apart because I had too many dragon decks
White decks dreaded facing Gloom for years, and they finally got to stymie their opponents' mana costs with an artifact/enchantment Gloom of their own
Blind Obedience is a staple and can be easily played in every white deck, not to mention that the art is stunning
They take a little work to set up, but just winning the game is a reward worthy of the effort
Illustrated by Mike Burns Standard Not Legal Alchemy Not Legal Pioneer Not Legal Historic Not Legal Modern Not Legal Brawl Not Legal Legacy Legal Comp
Thought Vessel, the most recently printed of these cards in Commander 2015 , is most reminiscent of Reliquary Tower, sharing the same rules text word for word, except it costs two generic mana to cast