Imp equipment

Imp Equipment is a special subset of equipment in Final Fantasy VI. The Equipment consists of the Impartisan, Tortoise Shield, Saucer, and Reed Cloak. In the original Super NES release, they were called the Imp Halberd, Tortoise Shield, Titanium, and Imp Armor. They can only be acquired from various monsters in the World of Ruin. The Impartisan can be won from Greater Mantises or stolen from Tyrannosaurs. Tyrannosaurs also drop Reed Cloaks, which can be bet at Dragon's Neck Colosseum to win a Tortoise Shield, then those can be bet for a Saucer. Saucers can also be stolen from Tumbleweeds, and the Pugs and Pug enemies can be Metamorphed into the equipment.

All the armor of the equipment absorbs Water and teach the Imp spell. What makes the equipment so unique from other subsets is two unique properties. The battle power of the Impartisan is 253, with only three weapons (Ragnarok, Lightbringer and Ultima Weapon) having higher battle power. The three armor pieces also possess the highest defensive statistics of any other piece of equipment. The only exceptions are the Force Shield (which provides higher magic defense than the Tortoise Shield) and the Snow Muffler (which provides higher defense than the Reed Cloak). On top of everything, the equipment is all universal, meaning anyone can equip them, even Gau who cannot equip weapons.

However, the second unique aspect of the Imp Equipment is that they only "activate" when equipped on a character with the Imp status. When equipped on a human the Impartisan has only 13 battle power and the armor pieces only provide a single point of defense (although they still provide magic defense). However, once the character is "imped", the true values of the equipment take effect. A character equipped with the full set of Imp Equipment and in Imp status, cannot cast spells as they are "imped", but will have maxed out defense, magic defense and battle power. In effect, only attacks that ignore damage, inflict status ailments or inflict Instant Death can harm them, making them practically invincible in the average battle as any other attack would only do a single point of damage.

Dissidia Final Fantasy
The Imp Equipment appears in Dissidia, and if the whole set is equipped, it increases the wearer's EX Force absorbtion range by 15m.