On the theory that Final Fantasy 8's Rinoa is really Ultimecia:

"No, that is not true," Kitase said. "I don't think I'll incorporate that even if we do remake the game. But that being said, both Rinoa and Ultimecia are witches, so in that sense they are similar, but they're not the same person."

https://www.kotaku.com.au/2017/09/is-squall-really-dead-final-fantasy-producer-addresses-the-series-biggest-fan-theories/