A super move is a special move that all characters have. To activate it press the super move icon in the top left of the screen below your character - be careful not to tap your character by accident or it will switch character.
To get this trophy make sure the super move icon is full (it will recharge after use), then on a level run around a bit when there are multiple 4+ enemies on the screen and get them to chase you.
Tap the super move icon and you should get them all in one move. Most characters can be used to get this if you have 4+ chasing you and they are near when activated..
If having trouble try with the red brick for Invincibility turned on ( found in Thorin's Revenge Story/freeplay mode - Right before the minecart)