Ixion
Ixion is the third Aeon that Yuna can summon. She receives it after the team completes the Djose Temple and the Djose Cloister of Trials. Final Fantasy X is Ixion’s first appearance as an entity that you can summon in a Final Fantasy game.
Overdrive: Thor’s Hammer
Ixion can do regular attacks as well as an attack called Aerospark. In addition to doing regular damage, Aerospark can also remove helpful status effects from the enemy, including 
Haste, Protect, Reflect, Regen, and Shell. Thor’s Hammer, Ixion’s Overdrive ability, is a lightning-based attack, so be sure that the enemy you are fighting is not capable of resisting or absorbing lightning magic.
Ixion will be able to break the 9,999 damage limit after you have obtained Kimahri’s Celestial Weapon, 
Spirit Lance, and upgraded it using the 
Saturn CrestJupiter Crest.
Note that the upgrade happens with the Saturn CrestJupiter Crest in the 
PlayStation
Xbox
Nintendo Switch version of the game. In the Xbox and Nintendo Switch versionsIn the PlayStation version, this item is swapped for the Jupiter CrestSaturn Crest. You can change the active version using the Game Version toggle in the sidebar menu. Refer to the Celestial Weapons section for a full breakdown of the differences.