Avatar cycle

All of the avatars so far, including Aang, have had four avatars in different groups. The Avatar Cycle is heard in the beginning by Katara; Water, Earth, Fire, Air. The "chain" before Kuruk's chain went in the order of Unknown wn Water Avatar, Unknown Earth Avatar, Unnamed Fire Avatar, who was shown in a glimpse of a vision that Roku was showing Aang, in The Avatar State, and ended with Yangchen.The next chain went in the order of Kuruk, Kyoshi, Roku, and has ended with Aang, the current Avatar. Since Aang is the current Avatar, it is unknown about the next Avatar. However there are four things known about him/her. 1. He/she will be the first of their "chain." 2. He/she will be a Water Avatar. 3. He/she will be born out of the Southern Water Tribe. 4. His/her guide and protector will be Aang, as Roku has been to Aang.