Press Space A max challenge appears sometimes when just doing normal battles, when it happens, you play as the mixel you were just playing as in the normal battle you just did. Whatever Max is in the shadow is the one you have to fight. You and the max both have one life. If you lose, nothing happens and it will be awhile until you find another. If you win, so will get a prize. The prize is different every time. You also are not allowed to use cubits during this. And if you don't want to do it you can pause and there will be a forfeit option.
credit to BFDIAM
