The whole game is battles...
using F1 to attack F2 to use magic and F3 to use a power move
the game implementa the AAM system which rates your attack, magic and power moves on your HP and MP

stats

KAIN

ATK- HP/2
MGK- MP*2
PWR- HP+MP

RYDA

ATK- HP/10
MGK- MP
PWR- MP*2

XERO

ATK- HP/5
MGK- MP*2
PWR- MP*MP

thus is all the info you need...