Revenge

When people successfully attack you, their name will appear in the Revenge tab, located on the right side of the screen. If you successfully revenge them, you can earn Upgrade Orbs, Evolution Stones, Lesser Runes, and either a silver key or a Mythical chest.

Mark a trainer as your enemy and defeat them up to three times a day. Only 30 enemies can be kept at once.

The Mythical chests give you a chance of winning these items:
 * Guardian Advance Stones
 * Mushrooms
 * Rider Medals
 * Flying Medals
 * Lesser Runes
 * Greater Runes
 * Perfect Runes
 * Refining Stones