Maybe regarding Klee, maybe future updates will show that Dodoco is "not Klee's imagination and is real and is badly influencing Klee/Klee inner evil personality projecting onto Dodoco(Something like Nadeko from the monogatari series projecting onto her scrunchie in order to justify that she is being influenced by the evil snake to do bad things when in actuality, it was all her)". Thus, Dodoco is directly or indirectly corrupting her? But I do agree that sometimes Klee's behaviour is off-putting. Including the one where
As for corruption of other characters, i think its great actually. Jean changes based on Klee's pranking progress. While everyone one acts like normal female adults, that has adult tendancies, with a few outliers like:
If you based your opinion, of corruption being weak, on the polaroid, especially the third batches from the third location, the old guy kinda said that he had enough photographic evidence to blackmail them, which explains their behaviour in the third batches of polaroid.
I do kinda wish in future updates, there will be personal quest and scenes (not including polaroid) of other characters, especially those that aren't from mondstadt. I wouldn't mind male characters being involved too tbh.