Also perhaps a completely unrelated point, but I really like how the game avoids the common trope of OP characters getting nerfed once they join the "Hero's" team.
Ginasta. You can say it was narratively justified but many games narratively justify it. It still happened.
Part of me wants to agree with you, as Ginasta is our weakest fighter, but to play devils advocate was she EVER really OP? She gives off that impression, especially with how she crushes the SkullCrusher in the first gathering, but he was only a baby bitch little shard king. I think ANY current Harem member now could do such a thing at present strength, Yarra even says to have doing so at the gathering. (In regards to all the fucklord remnants left over.)
But back to Ginasta, I love the her, but she does not really have an OP track record.
Ginasta Vs "Doom King"- Result: Failed, captured.
Ginasta Vs Incubuss Emperor- Result: Failed, injured but escapes.
Ginasta attempts to trap Sabitha- Result: Failed, captured.
Brainwashed and Tower charged Ginasta vs Simon and Crew - Result: Failed, needs to be mentally restored by Simon.
Ginasta vs LustLord- Result: Failed, captured.
So while I do love Ginasta, I would not really call her "OP". MAYBE she could take on some nobody like Fuzuko solo, like Sabitha can, but she isn't as good at tower delving to get to him like Sabitha is.
Her only real OP ability is an immunity/ability to cancel out Incubus control in herself and others, and she still has that. She offers to do that to the captured succubus, but you'd have to be a LOON to turn that orgy down.