But whats different about this manhwa is that she doesnt lose herself slowly, but something click in her just in one night. I think those type of changes r the scariest(⊙…⊙ )
this isn't an isekai story but ur right, just look at homura
While isekai not exactly an official term but more of what people have been calling these type of stories since it's popularity these days, regression is part of isekai since there's a change of body and/or soul across time and/or dimension. Regressions (aka turning back in time) are just not part of popular isekai types, since in Japanese media they commonly only use transmigration and reincarnation.
But yeah, Homura is one example of it. MC is still considered fine I guess since it's still in single digit and she still start off with a new method. When it's xxxth time regressing, it's just sad.
This is why regressor, especially repeated regression, is the worst type of isekai. With each regression, that person lose themselves even more. Same thing with time loop.
Yoo Joonghyuk should be glad that he stops at his 3rd regression.