If you are like me, you made many mistakes during this fight and the other fights. Here is an easy way to spare Mettaton EX: • When the bombs start falling, shoot them so they can’t destroy the blocks. • When arms start falling, shoot the yellow blocks. If you shoot anywhere else, the arms will fall faster. • When the disco ball shows up, shoot it so the beams turn blue, then standstill. • This should allow you to spare him.