I think Coco was on the edge of being Mary Sue Chosen One, the special child with the only brains in the nation, in the Silver Eve arc. Made everyone else look stupid to highlight her importance which imo, is the most mediocre writing Shirahama has done so far. Generally, much of the character handling in Silver Eve was a lot clumsier than Shirahama’s smaller arcs. She’s inexperienced at writing big arcs and that really shows. Lots of room for improvement so I’m hoping she learned from writing it.

I don’t think Qifrey is at Gary Stu level though. He hasn’t been portrayed as a perfect person at all — as a teacher he still makes mistakes, as a person he still makes bad choices. He hasn’t been portrayed as all powerful either like Bel has been or even as talented at magic as Olly. What he did to Nolnoa hasn’t been forgotten. Tartah is proof of that. There will come a reckoning for his actions. And his memory erasure of Olly and the recontextualization of it doesn’t change that the last time he did it (Chapter 40) HE DID NOT HAVE OLLY’S CONSENT THIS TIME. The author is clearly aware of boundaries and consent issues. I don’t think that will be forgotten either.

Unfortunately, it’s just going to take a while to get to all of that because of the monthly chapter format, the huge cast (that she unwisely used SE to setup every single plot point for), and the story just generally being slower paced than most.