Well, to talk about Isekai...
I really, REALLY HATE when Isekai use videogame system (level, skills, inventory, stat window, appraisal, etc...), even more when it's with something like "you gain ability of the ennemy you eat !", even more if it's a harem.
It's absolutely horrible. 99% of Isekai using this are absolute thrash, with some miracle here and there like
Fran and Daddy Sword .
It's really not good for the market, we got way too much copy/paste story with this.
I hate how Isekai Mc are most of time a teenager with black hair, even if he was 40 or 120 y old before.
I hate Isekai OP characters since the beginning with "cheat". Fucking thrash. What's the point of reading when you know MC will never have any problem/challenge ?
GUILD AND RANKS.
For cliché Rom-coms Harem :
- The first girl win trope. What's the point of a harem when you know since the 1st chapter how the story will end ?
It make only the others girls as fillers characters, and you feel bad for them, trying to gain MC attention in vain.
If a story is like this, it's most of time a really low quality manga, no need to buy it.
-Dumb MC. Oblivious to everything. shy until the end (will NEVER confess to his crush before he fall for Main girl ). Can't reject anyone, even when the girl is very annoying (hello Tsundere) or just a THOT.
Mc with alzheimer, how can they ALWAYS forget a big promise they did years ago as a child ? Seriously ? Even a Red fish have better memory than this.
-Girls loving MC for no reason, just because he is...normal, not even really nice.
And lot of others cliche.