[Chaos]

I'd say to make the mirror simply nullify the projectile instead of reflecting it if the damage is too high. If you're looking to one-shot a gunner with their own projectile, go invest 10 SP into Kensei instead of trying to bank it all on some mid-rarity accessory.

(That, and the Spirit Mirror is already far more useful than most higher-rarity items to begin with. It needs a nerf anyways.)