This applies only to ranged charachters:
Jumping then holding down the power button and pressing X while still in mid-air will make a ranged attack just as powerful as if you were on the ground but will cost much less power points.
This also works well with charachters who can fly. When they are thrown across the arena quickly press your flight button to stop yourself from htting anything. Then let go and press and hold the power button while pressing X to follow-up with a quick ranged attack.
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