Dragon's Stronghold

(Palaces are treated as lands. You may play a palace
in place of a land on your turn. The number at the
bottom right corner indicates the number of Palaces
with the same name you can have in your deck.)
Tap an untapped Dragon you control: Create a colorless Treasure artifact token with "Sacrifice
this token: Add one mana of any color."
Tap X Treasures or Dragon's Strongholds: Search
your library for a Dragon with converted mana
cost X or less, reveal it, and put it into your hand. Shuffle y