Mhmm idk if my advice will be super useful, especially since I think that it's mostly a matter of personal tastes, but I'll try to give my opinion :')
First of all, a "well-developed character" and a "character with a good TH bio" are two different things. Of course, they often go together but there are exceptions. You can have a good idea in your head, but difficulties to translate it in written form. (I know because I'm still struggling with this... I think my bios improved a lot recently even though my ideas are still the same lmao, it's mostly trial and error + slowing adding and editing stuff)
If you are aiming for characters with good TH bios for getting faves (don't worry, there's nothing wrong in wanting to get some recognition for your work, I'm saying this in a non-judgmental way), it's important to take a look at "popular" characters and members and see how they create profiles for their characters. As Kadrina said, people typically fav characters for their art, design and general layout over content.
First of all, a good way to have appealing characters is to have an appealing character icon and profile! Showcase the best artwork of your characters in their icon, gallery preview and even bios, and maybe add some aesthetic images as well; this way people can have the general feel of a character without having to read a long profile. It's a mix of publicity and "show, don't tell" imo
It's also a personal preference but I think that your collection would feel more harmonious if the layouts were similar, at least for characters in the same folder or just "group". For example, Raphael and Hermes are often linked together, but their bios follow a completely different layout and it feels kinda weird; keeping the same layout between all the cast of City Lights, for instance, would give the cast some harmonious visual identity.
Another detail that could improve navigation through your bios would be to link characters when you mention them, especially since most of your characters are part of the same stories and universe. When writing a bio, always imagine that this one may be the first one that someone will read. For instance, Celeste's bio mention Verdauga and Selene, but a new reader will have no idea who these two are unless they browse your entire profile. You can also use this to explain lore and other concepts, just like Wikipedia articles often link to other articles.
Giving advice for creating well-developed characters is a bit more complicated since just like I said at the beginning, it's mainly a matter of personal preferences, tastes, etc. I personally love characters I can relate too, characters who have to face the same, or similar difficulties that I do.
Adding "minorities" is a great way to diversify your writing and create characters diverse people can relate too, but I understand that it's not something everybody wants to deal with, since it often requires heavy research or/and personal experience. It may be difficult for you especially since a lot of your characters are gods, angels or other kind of immortal beings, so it may not always fit your lore. An alternative could be to have "coded" characters; characters who display some traits of said minorities without being explicitly stated as such. Of course, making a character part of some kind of minority should not be just done by slapping a pretty label on their bio, and "token characters" should be avoided as well, lmao; just do it if you feel like it, not out of "obligation".
Another thing I really like is "villain" characters who aren't 100% evil! Idk if you've noticed it but most of my "villains" (even if I don't have that much of them) often aren't unredeemable. They have good personality traits, and often do "good" actions, too! Life isn't black and white and while it's okay to have some punching balls, giving some good traits to a villian can give them more depth. "Are their actions still good if they were made by an horrible person?" is the kind of question I love lmao... And also really love the "does horrible things but is persuaded they are doing good" trope lmaoo
Sorry for the ramble, I just got inspired I guess :v Of course, these are just suggestions based on my own experiences and tastes! You're free to do want you want with your characters: the most important thing is to have fun writing them! I feel like I've just written some general advice and listed some little details that bugged me, it's difficult to give critique, especially since your characters are already pretty well thought-out in general!