if you need help leveling up, there is a highlight glitch you can do.
Go to highlights, and select either the "Greenhorne Royalty, Again" "Genie of the Lamp, Again" or "Fab Fairies, Again" Highlights. Now wait until the screen turns black and is loading the part where the characters regain their faces. During this part, spam the exit button. Done correctly, you should have to exit the highlights menu twice. Now the next fight you get into, it will be instantly cleared. BE CAREFUL, THIS GLITCH HAS CORRUPTED SAVE DATA BEFORE. But I think you'll be fine as long as you don't skip a story cutscene. Also, don't view the Battle you glitched, your game will crash.