If this is daylight obvious, ignore me.
I've read in the wiki that using charge melee + melee cancel to combo into normal melee for massive damage. I deem it not as useful as my ('the' if everyone knows it) double melee combo for SP3 only.
Works best when you catch your opponent near ground:
Charge melee attack(finish the combo!)
After the last hit, double tab booster to DASH. (consumes 1/3 EX gauge)
Normal melee--SP3 will start slashing away at its immobile target, missing on one of the first three hits, hit on the fourth and fifth.
WARNING: SP3's charge melee is not enough to build up 1/3 of EX gauge required for the dashing part.