Elemental exploits do help a bit. There are three different elements in this game: earth, fire, and shadow. Earth beats fire, fire beats shadow, and shadow beats earth.

During fights elemental weakness adds around 10-15 power to your overall attack power.

The outcome of a match is determined solely through three factors:

Your champ's base power - affected by how high your champ's level is and whatever equipment they have on.

The training results - rain regularly to keep your character ahead of the competition. At least once between each fight.

Hitting an elemental weakness.

Straight slashes nets you higher combos during training.

Avoid the bombs while swiping at the balls.