[Eldecrok]

I would like to propose a few upgrades to the Prism Gem, and its components. We have a few options.

Option A: +10 Damage for a domain of magic for one spell.
Similar to the Spirit Mirror, this option would proc only once. Simple enough, the only problem would be for something like Exgalfa, which we could limit to the first Fireball, or even just divide the damage over the spell duration, or even just apply it at the end. I recognize though, that multi-type spells (Holy Spark, Scarlet Twister), benefit a bit more from the Prism Gem than others. Even so, I think this might be a viable option.

Option B: Extra Status Resistance to one instance of a status effect.
This would be a bit new, but this option shouldn't be too hard. It would function a lot like Arcane Tattoo (Warding), but for the specific status effect.
Fire -> Burn. Ice -> Frostbite. Wind -> Lingering Damage. Earth -> Magnetize. Light -> Blind. Darkness -> Poison(?).
Edit: We could just give immunity to this specific status.