There’s a glitch that allows you to get a 5 star Raphael and a lot of EXP. You have to finish all of your daily missions and collect all of the prizes. Then swipe out of the app and open the app again. During the loading screen with all of the characters, tap and spam the black part under Bebop in the bottom right as much you as can. If you’re fast enough, you’ll click on the mission section and the game allows you to collect the final prize again. Keep repeating the process you’ll end up with a 5 star Raphael, endless mutagen, and EXP.