[Snake]

A free revive once per fight? I mean, sure. That works. Make it a flat 15-20% HP recovery and a flat 15-20% FP reduction (and the inability to proc if you can't pay the FP out). I disagree with FAI being required only because that can be a little too absurd on people who can already heal themselves up, needlessly prolonging the fight way too much beyond comfort.

Also. As of now, Avalon can stack with itself, so... Maybe different accessories enchanted with Avalon can increase the amount of revives you can do per fight too? (Or just proc twice for a bigger heal when reviving, this is also a good option in my opinion.) That only goes to weapons, so it would be two max.

After this, Interference will sure have a little more value to keep people down.

Also, Dev, don't forget to put some fluff text warning like "--But a gentle, golden light envelops [X], as they refuse to go down!"