Invincible

Description
User cannot take damage.

Strategy and Synergy
Effects that give Invincibility are often good with spells that require you to position in a specific spot for a long period of time such as Infinity Beam, Rest, and EXPLOSION!. However, Ghost Costume is only for a brief period at the very start of the fight - making it more difficult to exploit unless you get one of the synergistic spells early, and Pocket Sand demands that you Shuffle, meaning you won't be able to cast a spell right afterwards.

Trivia
The invincibility icon is a ghost, as ghosts are generally thought to lack a corporeal form - thus making them invincible to conventional attacks.