Nullifies magic element.Description
Mag Elem Null is learned from Promist Ring and Protect Ring for 115 AP. Promist Ring is first bought from Treno Auction House after the Blue Narciss is available, and the player can also find it in Desert Palace and synthesize it in Daguerreo.
Protect Ring is found from using a Dead Pepper at mountain crack on eastern part of Lost Continent while riding Choco as soon as the player has the Blue Narciss and has advanced in the Chocobo Hot and Cold game far enough to have Dead Peppers available. The other ways to get the Protect Ring are in the endgame, or from excess playing of Chocobo Hot and Cold and then buying it from Mene.
With Mag Elem Null equipped, Vivi's black magic spells are always non-elemental with properties otherwise unchanged. Enemies cannot absorb or resist damage from them, but Vivi cannot exploit enemy weaknesses either. Elem-Atk gear still works to boost damage, however. Mag Elem Null affects spells returned with Return Magic.
Mag Elem Null is niche as Vivi already learns some powerful non-elemental spells (Drain, Demi, Bio, Comet, Meteor, and Flare) and enemies tend to resist only couple elements while still being damaged by the rest, and Vivi learns a repertoire of elemental magic since the start. The only enemy that absorbs all elements is Gimme Cat whose only purpose is for gil farming. Making Doomsday non-elemental would be a hindrance, as the party could no longer absorb its Shadow damage for sustenance. Vivi can also defeat enemies without dealing damage with Break, Death, and Stop.
Mag Elem Null also takes a lot of AP to master and the two equipment pieces that teach it cannot be worn simultaneously to speed up the process. It also takes so many Magic Stones to equip that it couples poorly with Vivi's standout support skill: Reflectx2. Reflectx2 doubles the power of a reflected spell, stacking with enemy weakness and Elem-Atk gear. Against an enemy that resisted elements, the player could couple Reflectx2 with Mag Elem Null and still get the boost from Elem-Atk against them. However, once Flare becomes available, Vivi should just cast that.
Mag Elem Null could potentially be useful during the brief window Water is Vivi's most powerful spell against enemies that resist Water damage, though the enemies should still be weak to something else that Vivi can use. It could also be used with Return Magic against enemies who absorb damage from their own spells.
Instead of using Mag Elem Null, Amarant can be brought along to make an enemy weak to a random element with Curse, though this will not work to make Ozma susceptible to Shadow without completing the friendly monsters quest.