Hello, I remember the mc was a genious (he made a remark something along the lines of “If you cant learn a new language in a day (or in a week) you are an idiot” there is also the female lead who is in a prison/dungeon who is similary a genious withe whole language thingy. Not sure about this part but i belive the mc was a deamon and this was one of this revenge stories/cruel mc. Thanks in advance!