Give it an effect like prox det. That would make it unique.

I reckon remove the cap on the damage but cap the shield out much like how conjured ward and annulment works. This would effectively increase damage however you cant just go overboard and stack into health.

Or they can just up the cap on the damage return which is kinda boring but it works too imo

I always hope subpar abilities are tomorrow's (future) OP abilities when ZoS decides to mix up the Meta