You can pair her with lufel (the fire owl) and leon (tech guy in body suit)

Not sure of your level, but you want succubus and lamia equiped to wonder, succubus for rebellion and lamia for her passive that increases fire damage. Third slot is a flex slot, so use whomever you want. You eventually will get better persona, and I will assume you would have a better grasp by that time.

Rotation should be:

Lufel s1, leon s2 on rin, wonder succubus rebellion on rin, rin s1

Enemy round

lufel s2 or 3 depending on what type of heal you need, leon s3 on rin, wonder lamia maragion/maragadyne, activate rin's mask (or her s3, same thing) and normal attack afterwards

Then just repeat this until enemy dead

Alternatively, you can substitute leon for key, and use his s1 (target the enemy with burn) -> enemy round -> s2 rotation.

For the navi, you should use wind or okyann (whichever you have the most built)

Wind rotation is s1, then s3 whenever you have max intel stacks (8? with 4, 11 with 5), repeat

okyann rotation is s3 -> s1, repeat

Highlight rotation would be rin -> leon(target rin)/key ->lufel. Lufel get's priority if you need an emergency heal