Amount of damage depends on the enemy's HP.
Demi Shock (グラビデ拳, Gurabide Ken?, lit. Gravide Fist), also known as Gravity Fist, is a recurring ability in the series. It is similar to the Gravity spell, inflicting damage based on a percent of the target's HP, and is usually associated with Amarant Coral.
Damage one enemy for 1/2 HP
Gravity Fist is an active, special ability learned exclusively by Amarant (level 12 (4★)). It allows the user to inflict 50% damage to an enemy's HP at the cost of 12 MP, having the same effect and cost of a Gravity spell.
Demi is a prefix meaning "half," from the Latin dīmidium meaning "divided in half."