So i'm looking for a manga or a manwha (i don't mind which one) where any character - though preferrably the main character - is an ex-something (like assassin, master of something or just generally OP), but either hides it or left it behind to go to school/work.
Then the past catches up to him/her, either bigtime or just some small issue/rumor.
I hope that this description was clear enough for you to understand what i'm looking for 😀

You could try: Aiki, ?Berserk?, Black cat, King of Hell (manhwa), riki-oh, rurouni kenshin, samurai deeper kyo, Shin Angyo Onshi (manhwa), Trigun, Ubel Blatt, Until death do us part, Wolf Guy. This are all i know hope i helped you 😀