Xiao is an Yaksha, the highest rank of a group called 'Adepti'. Adepti is a strong assassin group filled with the best assassins, be it in using different weapons or having good physical strength. There was once a number of Yakshas in Adepti but they died during a mission, leaving Xiao to be the last one left. Due to his friends' death, he had grown cold and quite distant to the rest of the assassin members, purposely not coming to meetings and hangouts. Maybe you'll be able to help him?