I don't know if this has been suggested before, but what if we could cast auras on the enemy that have a negative effect on them? Here's some ideas of 'Negative Auras' to help you imagine what I'm thinking:
Duality - 4 pips, anything that happens to you, affects him, and what happens to him, affects you for 4 rounds.
*Basically, if they cast a Ra on your team, when it hits you, it will also hit them. And if they cast a Balance blade, you get one too. If they cast a Fairy, you heal too. But as a sort of balance, if a Ra hits them first, it hits you too, same with the other demonstrations.*
Dubiety - 4 pips, -40% accuracy to the target for 4 rounds.
*This is pretty obvious, Dubiety is when you hesitate, so this makes you hesitate too. This is why I made them cost pips.*
Debilitate - 4 pips, -75% to incoming & outgoing heals for 4 rounds.
*Good for when your target needs to heal before you finish them off.*
Attenuate - 4 pips, -30% to all outgoing damage for 4 rounds.
*For when you need to heal before your target finishes you off.*
These are just a few ideas, and I'd be interested in what you can come up with.