"[4 Turns] Isabelle disables several power limiters to buff all stats except LUK by 100%. Costs health every turn!"
Cost: 25 TP
Source: Ganguro Isabelle - Starting skill
Raging Maelstrom is a skill that places the user into a super-charged buffed state for four turns at the cost of 20% of their Max HP each turn. While in this state the user's ATK, DEF, MAT, MDF, and AGI are all doubled, and they receive two actions each turn. Note that these buffs are not the same as a normal STAT Up effect. While the effect of Raging Maelstrom is active, in its place is Raging Maelstrom Off which allows for cancelling the state early.
As is immediately obvious, this is an extremely powerful skill that increases Isabelle's damage output to extreme levels. The cost of it however is prohibitive, and means that it is not something worth using against regular trash, but may be helpful when pushing to finish off a boss.