Responses
This one is similar
https://www.mangago.zone/read-manga/magic_academy_s_genius_blinker/
This one is side character trapped in webnovel
https://www.mangago.zone/read-manga/trapped_in_a_webnovel_as_a_good_for_nothing/
I don't remember much except that the protagonist is not the main character of a webtoon. Like he died and became q side character in a sort of magic school. They had to choose weapons and he chose the one he thought wasn't strong at all. But it was actually a rare one that not anyone else could use. Of course everyone thinks he's useless and he sort of proves them wrong later.