I've read a manga like this before but as shoujo
http://www.mangago.zone/read-manga/e_rank_healer/
She was also an outcast in her last party, deemed useless and what not but i liked that she was a diamond in the rough / they just didn't know her worth
NOW THIS STORY , i don't like that he's op just because of a book / accidental, his special trait is accidental and isn't by his merit (alone)
Like, his value increased BECAUSE of the book and not "He was valuable all along"
I'll still read it since this is just a minor issue for me and it's still less than 3 chapters in
That was so stupid
I know! I felt compelled to read it due to its stupidity!
Fantasy theme mangas are getting weirder.