Draco was the undefeated champion in dragon battles, until he was defeated by a scruffy green dragon with fiery halitosis breath. Intent on finding this dragon, the boss promised Draco to locate him using the Dark Alchemist's technology called. "Find My Nemesis GPS Locator." The only thing Draco knows is that this dragon's name starts with the letter "O."
Each mastery level adds another card to the cardpool for defeating Draco. Each of the bronze, silver, and gold mastery levels unlocks a new card, while it takes all three diamond and onyx levels to unlock a single card.