Terra Cheesing Strat
 
STEP 1: Unequip ALL Combo Plusses, Finisher Plusses; make sure Aerial Finisher is UNEQUIPPED (NOTE: I'd unequip anything starting with "Aerial" for safety).
STEP 2: Make sure Negative Combo AND Fenrir are equipped on BASE Sora.
STEP 3: Jump at Terra, then do ONE finisher (which should come out immediately), and land.
STEP 4: Repeat Step 3 until one of you is dead.
STEP 5: ENJOY YOUR CHEESE WIN, SIR.
OPTIONAL: Summon Peter Pan to add to the cheese factor.