Shell

Shell (シェル) is an ability that appears in Kingdom Hearts: Chain of Memories, Kingdom Hearts Birth by Sleep, Kingdom Hearts Re:coded, and Kingdom Hearts 3D: Dream Drop Distance. It reduces the damage the user takes from magical attacks.

Mechanics
In Kingdom Hearts: Chain of Memories, Shell is an enemy card effect that reduces damage from magic attacks by 50%. It costs 50 CP to add to the deck and lasts for five hits.

In Kingdom Hearts Birth by Sleep, Shell is a Dimension Link ability.

In Kingdom Hearts Re:coded, Shell is an Overclock ability that vastly reduces damage from magic attacks.

Kingdom Hearts: Chain of Memories

 * The Ursula enemy card has Shell as its effect.
 * The Black Fungus enemy card can randomly activate Shell.
 * The Darkside enemy card can mimic an enemy's Shell.

Kingdom Hearts Birth by Sleep

 * The has Shell as its level 2 ability.

Kingdom Hearts Re:coded

 * The Kingdom Key 2.0 and its upgrades have Shell as a level 2 Clock Ability.
 * The Lady Luck and its upgrades have Shell as a level 2 Clock Ability.
 * The Oathkeeper and its upgrades have Shell as a level MAX Clock Ability.
 * The Metal Chocobo: Au and its upgrades have Shell as a level 3 Clock Ability.

Origin
Shell is a recurring status in the Final Fantasy series. It generally increases the affected character's defense against magical attacks, and it is usually applied with the spell of the same name.