So, I know that in LoK, "Tenzin" is Aang and Katara's youngest son and the only airbender. I decided against using it for one of his AU-children, but I still like the name very much. So, in this, "Tenzin" is Aang's biological father, because I think it makes a nice connection. (As Gyatso, Aang's father figure, is clearly named after the current Dalai Lama, who's name is Tenzin Gyatso, which probably is the reason for Tenzin's name in LoK, too.) So, you know ... that's the reason for that. Sorry, if that is confusing for the people who've watched LoK.
11. tenzin and aang
"The Avatar, huh?"
He couldn't look away from his son, who was happily playing with his new toys, the toys that had changed his little life forever without him even knowing.
"That means I'll have to leave him here, doesn't it?"
He could hear his former guardian step closer, felt a strong hand grip his shoulder.
"It's tradition for the Avatar to be raised at one of the temples, son. And it's probably the best you can do for him, with the political climate how it is at the moment. He's going to need all the training he can get."
"He is my child, Gyatso. Everything that's left of Aanjing."
He dragged a hand through his wild hair.
"I don't know what I'd have done without him ..."
"It is your decision, Tenzin."
"They won't let me leave with him. You know that. For all the open-mindedness the Air Nomads are praised for by the other nations, you know how stuck in their ways the Elders are."
He sighed.
"He'll have a good life here."
"You know he would."
"I want you to be his guardian, if I do this. I know you'll care well for him."
"Consider it done."