Soon after , Aang meets a guru who attempts to teach Aang to open his seven chakras in order to control the defensive ` Avatar State ' ; but when Aang perceives Katara in danger , he leaves before the seventh chakra is opened , and thus loses his progress until the seventh is opened .
When Aang has a vision of Katara being in danger , he leaves the Air Temple where he is being taught before the seventh chakra is opened , locking it .