Find Your Rival:
Choose 2nd Impact when you have the choice of playing either New Generation or 2nd Impact. Goto Options and set the Difficulty to at least four stars.
Now, choose Arcade mode and pick a fighter and Super Art. Now, within the first four opponents, three of the four must be finished off with the Super Art. The fourth opponent MUST be finished with the Super Art. It doesn't matter which two of the other three are finished off with the Super Art. After the defeat of the third opponent with the Super Art, a message will appear stating "Your Rival has Found". You will then be challenged by your rival, with a short exchange of written dialogue on the VS screen.

Play as Gill:
Just beat the game on any difficulty level with any character