Hinata and Mizuki are skilled in elemental magic. Hinata is skilled in Fire Magic while Mizuki is skilled in ice magic. When they reach their adult forms Hinata can start using lightning magic while Mizuki starts being able to use water magic.
Adult forms are always stronger than kid forms ;) They also have a third form, her true form which is them combined because originally they were one person but this form would probably only appear in the Twinrovaish boss battle o;
I think I OP'ed my characters, lol. Jeeze me telling you not to OP your characters when I've totally Op'ed mine. Man I'm a hypocrite. Lol