Ixion
Location: D'jose Temple
Unique Attack: Aero Spark
Causes non-elemental damage. Also negates: Protect, Shell, Reflect, Haste, Regen, and the Nul.
Magic
Black: Thunder, Thundara
White: NulThunder, NulWater
Overdrive: Thor Hammer
Obtaining Spirit Lance, Kimahri's legendary weapon, allows Ifrit to break the 9999 damage limit.