When somebody attacks you, you can perform a revenge attack on them from the Defense Logs. Unlike retrieve attacks, revenge attacks are real, which means that you are attacking the actual dungeon of this player. Therefore, the totem can be broken, could contain no gems, and the player themselves could be online or under shield at the moment. With revenge function, you actually steal gold and gems from the player who attacked you. Once you have performed the revenge attack on someone, they cannot get revenge in return.