Sinronce, Jewel of the Goldsea

Treasures you control have hexproof.
Whenever a Treasure token enters the battlefield under an opponent's control for the first time each turn, create a colorless Treasure token. (It's an artifact with "{t}, Sacrifice this artifact: Add one mana of any color.")
Whenever you sacrifice a Treasure, add an additional mana of any color to your mana pool.