Dyna (Illura)

Illura -- namely, the city of Lumina -- is the first of the worlds that Dyna and Sascha go to, with Sundae tagging along.

There, both Dyna and Sundae become human and, before they are able to take that in, are told that they are contestants for the Magus Gauntlet -- an event celebrating the history of Illura. They are all given amulets to use the power that the Magus once had, and their goal is to fight off the people within the city. Sascha, naturally, sees this challenge as a great way to show how strong she is, and heads off to do just that.

After a few battles, they learn that the amulet's power isn't just them getting powers -- but sometimes, the original owners of this power taking over their bodies. It happens to everyone at least once, but the most notable is when it happens to Sascha, as one clear cut, super important fact is learned.

Sascha can't see without glasses.

Dyna, the person who had gone countless loops of time trying to save her in the past, and now in a whole new world, had just learned of this information. Just now! 

By the end of the competition, Dyna vows that somehow, in some way, he's going to find a way to get Sascha to wear them. They also get kicked out of this universe as a whole, and told not to come back -- it seems that this wasn't the first time an out of universe person hijacked their competition and won...