Opinions
Feels like you're leaning in wayyy too heavily on the drama/basic villainous caricatures/strawman stereotypes in oni/dragon girls' worlds to the point that it's not fun to even bother with those routes, the heroines themselves are likable out of context but their routes/worlds are not fun at all they feel unnecessarily morbid.
Also I think the power creep is going to become a major issue sooner rather than later at the rate you're going.
I really enjoyed Iris/Lila's content as a mostly self contained story but that's about it. The elf's character/route/world felt empty, like the character is just a haughty plot device instead of a person. Dragon/Oni girls despite being pleasant people weren't fun due to their routes.
Suggestions
I suggest removing the excessive hate against the characters from their worlds just let people find a poison dragon unattractive on the basis of the poison or finding her naturally unattractive because they have different tastes in appearance instead of tying it into a racism subplot(meaning they pass her up or ignore her NOT actively antagonize her), let her insecurity be a natural character flaw to overcome instead of the result of systematic oppression, as for oni girl at first her world sounded really fun, I was hyped for a role player from a technologically advanced world playing in a virtual world(oni girl) unknowingly interacts with real magic subplot like the one in tsubasa reservoir chronicles given how the first few moments played out, where the different sides(including the people playing purely monster races) act all edgy and antagonistic against each other when there's conflict but all get along well with each other once the competitions are over, instead there's just more mindless hate for no good reason. I'd recommend reducing how morbid the situation is with that world somehow, maybe don't make it so the world is designed to encourage wars of extermination/extinction. I hope that the elf/wolf girls' world's don't devolve into unjustifiable hate/discrimination narratives for no reason/just for the sake of drama.
Oh also it might be a good idea to just have the boss lady(succubus) allow the player to wonder the other worlds to visit the girls on his own with the warning that she won't bail him out or that she gets to keep his soul if she's ends up having to be the one to save/revive him(effectively a game over), just not allowing the girls' to visit the players world since she doesn't want them there for some reason, it's apparently where the succubus is based maybe she just doesn't want them causing a scene/drama there as a result, or if you wanna lean in on the elf's conspiracy theories you could go with that. Having the succubus give him a means of teleporting but only if he accepts ending up naked would fit thematically and could be what the elf reverse engineers to give her something to gloat about, she could still end up in the players world naked by testing the spell/breaking the rules. It could enable two modes for visiting the girls, a less time restrictive naked version from the succubus for socializing, raising the stakes with sudden encounters, or prolonged stays and a time restrictive but practical version that allows him to bring stuff that he can carry with him(no matter what the stuff he brings goes with him when he leaves though, can't have them abusing the spell to game the system excessively), can still have the summonable equipment just as an extra for emergency/combat thing(I'd advise against it working with naked mode for the sake of limiting power creep though, if you really want to give the naked transportation protection maybe consider a fast/strong barrior spell that burns mana fast, good for a last second save but completely impractical for actual combat).
Lastly a gameplay suggestion
Instead of blocking the player from doing stuff if they haven't progressed far enough in another route to get special gear/moves/macguffins allow the player a stat check(maybe check for more than one stat), if the player passes let them accomplish the feat without the special macguffin, if they don't let them game over, this allows the player a greater sense of control/freedom, maybe adding a save warning before the checks regardless of the macguffin could work but that could just annoy people instead, hm... maybe add warnings before checks but allow the player to toggle them off in options. Point being allow the players to choose where they go enforced play order/restricting choice can make people question why you bothered adding the hub area with such few choices, instead of going full kinetic novel. (Only disabling rollback when you're in the arena would also be nice, renpy without rollback just feels weird.)
