A Super Move or Ultimate Move is a special technique that's performed when a Hero uses their Quirk to turn the tide of battle and make a big impact on the opponent.
The function of any Super Move is to provide an advantage to the user in hopes of them winning the battle. These techniques should be unique to each hero or villain and it should push the limits of one's Quirk to exploit the aptitude of someone's fighting style. Super Moves do not have to be attacks, they simply must give the user an advantage over their opponent. Super Moves can be offensive, defensive, or supplementary based on the type of Quirk they have.