This article's content is accurate to the most recent public game version, 0.4.8d.
"Isabelle's signature spell with significantly more area of damage. 50% chance for Stunned against any enemy."
Cost: 12 MP
Source: Ganguro Isabelle - Starting skill.
Lovely Lightning Storm is a spell that deals moderate 
Thunder damage with a 50% chance to inflict the 
Stunned status effect to all enemies.
This can basically be considered a multi-target version of Lovely Lightning, dealing the same damage and having the same stun chance. Any time you are facing multiple enemies, this move becomes a very respectable means of both dealing damage and disabling opponents.