- All named sorceresses in the game have a wing motif.
- Sorceresses are natural magic users who do not need or use junctions, Ultimecia does it out of desperation during the final battle because she's losing. She has no GF amnesia.
- Sorceresses don't live forever, Ultimecia is the only surviving sorceress in her time and there have been sorceresses in the past before Squall's time.
- Ultimecia doesn't know about Griever before she faces Squall in the final battle, in the JP script she creates the monster out of Squall's thoughts and emotions because the game is about Squall's emotional journey and this is the payoff. Squall invented Griever to cope and by defeating a literal manifestation of it shows that he no longer needs it.
- VIII specifically has a happy ending because Laguna's ending was already bittersweet: both women he loved are dead, he couldn't return to his wife in Winhill and never saw his son grow up. Ending the game with Laguna's son killing Julia's daughter and both being miserable forever would be stupid and the kind of trash only illiterates on /v/ could write.

The real issue with Ultimecia is not that she's the alter ego of a previously introduced character because that's not a thing, it's that Ultimecia is a villain but her role is to serve as a challenge Squall can only take on once he has completed his character growth and because of that she's more of a plot device than a character. She has some characterisation through her actions in the past while possessing other people, and maybe the writers painted themselves in the corner by creating a time loop plot where Ultimecia's causality dilemma can't really be resolved and it leaves her in an awkward spot where she's a bit too pitiable for someone you're meant to kill.