Koh Rabntah / Noah
They both have a rather sad story in ARR.
Koh was so young when coming under possession of Noah. Based on the Lore Book, this “temporary” situation is an ongoing one. And based on the game itself, this hasn’t been resolved.
I did have a plotline brewing where Amon has promised Koh and Noah that he’d find a way to restore them both to independent bodies. I haven’t forgotten about this, but I backed off on it just a little to see if the FFXIV team remembered Koh and decided on some kind of story for them. I’m still waiting, to be honest.
The reality is, we have a lore-based Allagan soul with the mind and knowledge of an archmage sitting in Eorzea. Thankfully, Noah chooses to leave things as they are and seems to want Allag left in the past.
BTW, Noah… smoking is a bad habit and smoking while in someone else’s body is downright rude!