Strong Gambit
Once your characters get to about level 30, use Sunfire, Bishop, Toad, and Gambit as your team. The idea is to pump up Gambit as much as possible. Put as much of the stats you can into each ability as follows: Sunfire = Flaming Fury, Bishop = Energy Fury, Toad = Secretion, Gambit = Energy Form. Also, throw an extra 6 or 7 stats into each characters Mutant Mastery so that they will recover EP faster. During game play, activate all the abilities listed above and switch to Gambit. He will be able to run very fast and be super strong. Eventually he will have +200% movement, +400% or more attack and many of damage and defense bonuses. Also, because they regain their EP fast, you can reuse the abilities as soon as the affects wear off.