Hello! I wanted to ask, in The Avatar and the Fire Prince AU, how does reincarnation (The Avatar Cycle) works? In Canon, the Avatar is a human soul (Wan) who after death reincarnates on Earth in a new body to live a new life with the Spirit of Peace (Raava) bounded to it. But how about in your AU? I'm asking because I want to know whether or not we're going to have a scene with Aang having an existential crisis over the fact that in his previous life he was Zuko's great-grandfather.
Hello anon! :) Yes, I do my best to ensure that my AU is as canon compliant as possible when it comes to lore (including all known lore from Legend of Korra, the comics, the TTRPG, and the Chronicles of the Avatar novels), so the Avatar Cycle does indeed work the exact same.
I honestly haven't given a ton of thought to Aang and Zuko's reaction of who Roku was (though it will definitely still be revealed at some point just like in the show). While I think they would both maybe find it a little weird of a coincidence at first, I don't think it would cause either of them to freak out or anything lol.
We've definitely seen weird coincidences/connections like this before with other Avatars - for example, Kuruk and Hei-Ran were past lovers (before he met Ummi), and then he was reincarnated as Kyoshi, who fell in love with Hei-Ran's daughter Rangi. Then we have Korra, who was taught waterbending by someone who is basically a grandmother figure to her (Katara), and who was also technically "her" wife in her past life. She was also taught airbending by someone who is a father/uncle figure to her (Tenzin), who was also technically "her" son in her past life.
In general, there seems to be an understanding amongst everyone in the world of AtLA that each Avatar is very much their own distinct person, each with different lives, memories, and personalities. Sometimes more spiritual people - like Toph for example - can see that the Avatar has the same spirit/soul, but again, even Toph knows Korra is her own person and not just Aang with none of his memories lol.
Of course, if Aang had a problem like Yangchen did in which he was constantly having flashbacks to memories from his previous lives, then I'd say that yeah lol, he'd be much more likely to have an existential crisis. But as far as we know, Aang does not have any "memories" of living as Roku or any other previous Avatar - he only views previous Avatars' life events from an outside perspective. And even if he did have the ability to "remember" living as Roku, at least he wouldn't be able to "remember" actively being a grandfather to Zuko, since Zuko and even Ursa were born decades after Roku's death. That would definitely be awkward if that wasn't the case lol.
All of this has actually got me thinking about the theory where an Avatar could possibly reincarnate as their own child/grandchild/relative, especially with mixed-ethnicity/nation families becoming more common in the time of Korra. Like, say an Earth Avatar dies right as their child with someone of Fire Nation descent (or their grandchild, or sibling, or cousin, etc.) is born. As long as they have the right DNA, a relative of the Avatar could theoretically be the next Avatar in this scenario. The closest thing I could compare this to is like a Steven Universe situation (where he kind of both is and isn't his own mom - it's hard to explain if you haven't seen that show lmao).
Anywayyyy sorry for the long ass response anon lol. I just love talking about AtLA lore! :)