The Agents of Shadow is a secret organization of 13 warriors. They operate under General Phai, who takes orders from Lord Kala. Many have assumed friction between Kala and Phai. But this has been proven wrong. They fight using an unique battle system. They appear and challenge a member of Mario's team. Most of the time they challenge either a character or a partner to a duel. Defeating all Agents of Shadow is optional, and some such as Yozhi and Phai are required. But defeating all agents rewards the player with a special secret character. After the Agents of Shadow are exterminated, a short scene shows Phai and Sycho in a conversation, whoever they are never faced again. This could be a new game featuring the agents of Shadow once again, however this is just speculation.