This article's content is accurate to the most recent public game version, 0.4.8d.
"Marianne used this spell as a finisher for some time. Deals high Thunder damage to all enemies."
Cost: 20 MP
Source: Marianne - Starting skill.
Voltaic Punishment is a spell that deals high thunder damage to all enemies.
This spell is the bread and butter while using Marianne. With her obscenely high stats, it will deal accordingly high damage, easily clearing away entire packs of enemies. This spell's high MP cost is rendered insignificant by her also nonsensically large MP pool.