Can A Doomed Timeline Be Fixed To Be Non Doomed? Also, Is Being In A Doomed Timeline Predetermined By The Game, Or Is There Just A Certain Choice That Determines Whether Or Not Doomed Timelines Occur?

Aranea theorized a Doomed Timeline could be fixed by a skilled Sylph. Obviously not a Sylph of Light, but by a Sylph of Time, maybe. And all doomed Timelines are predetermined. Everything is predetermined, even the retcon was predetermined, if it wasn’t the cherubs wouldn’t have existed before it happened.