Something something powerwank.
Overpowered is love, overpowered is life.
Certain magic systems in my multiverse would indeed have different ways of interacting with physics and magic rules, so I concede a point from a long time back about something similar. However, past a certain level, all magic would begin to disregard normal physics as a universal fail-safe so you don't destroy reality. My multiverse would seem to have a speed advantage as a result of getting away with this thanks to the fail-safe.
Speaking of making Evvie older/more experienced, I have a few problems that would need to work out.
1. In the nexus she's already shown up as a child, which the tournament is incredibly likely to be canon within the upcoming multiverse. She'd have to be killed in the tournament, die again outside of the tournament, and reincarnate as an adult Evvie in time for the multiverse. Reincarnating as an adult wouldn't be out of the question completely if something strange happens, although she'd also need to maintain memories through this reincarnation to be considered an adult still. Well, a single strange event could account for both of these thing if you guys really wanted to push this idea.
2. Her personality sort of relies on her being as young as possible, her being in mid to upper teens already pushing it. Seeing an adult behave like she does would draw many strange looks and feel out of place. She could still have an interesting personality while dropping other personality traits of hers, although I like her personality now so would hate to see some of it dropped so soon without exploring it in a long lasting multiverse.
3. The root of Evvie's main weaknesses is intellect. She'd still have some weaknesses like cold but would be much, much harder to exploit and could be considered cheap without further nerfing on her abilities.
EDIT: Maybe Evvie was invited to the nexus as a secret plot by a dreamer to have her killed and reincarnated into her goddess form somehow, only not as a transformation but as a base form that she slowly grows more and more powerful in. Don't know why they'd need to conspire her murder like this rather than just doing it themselves though. Or how they could force a goddess reincarnation.
LeeRoy