Final Fantasy X/Aeons

Valefor


Valefor is the first Aeon that Yuna can summon, which you receive in Besaid, after conquering the Cloister of Trials. She looks like a large eagle, and therefore enemies on the ground have a harder time hitting it than other Aeons, because she can fly. Although Valefor starts out as a useful asset to your party, when you get the other Aeons, she will probably end up weak. Valefor's damage will be able to exceed 9,999 once Yuna activates her Celestial Weapon, Nirvana.

Special Attack
Sonic Wings

Valefor attacks an enemy with a burst of air from its wings. This attack can cause delay in the opponents turn.

Overdrives
Energy Ray, Energy Blast

Valefor is the only Aeon with two Overdrives. Energy Ray is the default Overdrive, in which Valefor shoots a ray of energy under the enemies, blowing up the ground under them. Energy Blast is a more powerful version with a longer recharge time that can be obtained by talking to a little girl with a pet dog in Besaid. Energy Blast is a lot more useful than Energy Ray. She will attack the enemies with a large energy beam through a spinning disc (often killing the subject).

Ifrit
Location Found: Kilika Temple

Unique Attack

 * Meteor Strike:
 * A Non-elemntal attack.
 * It has a longer recovery time than a regular attack.
 * Long-range.
 * Penetrates Protect even though it is a physical attack.

Overdrive

 * Hellfire:
 * "Ifrit encases its foes in a swirling ball of fiery vengeance and detonates it for massive damage to all enemies. All of Ifrit's attacks can exceed 9999 HP damage once you have activated Wakka's legendary weapon, World Champion." - Final Fantasy X Official Strategy Guide.

Ixion
Location Found: Djose Temple

Unique Attack

 * Aerospark:
 * Non-elemental damage
 * Negates magical effects:
 * Protect
 * Shell
 * Reflect
 * Haste
 * Regen
 * Nul Spells:
 * NulBlaze
 * NulShock
 * NulTide
 * NulFrost

Overdrive

 * Thor's Hammer:
 * "Ixion envelops all enemies in a storming vortex, and then disintegrates it. Lightning-based elemental damage is inflicted against all enemies. Ixion can inflict more than 9999 HP damage once you've activated Kimahri's Spirit Lance." -Final Fantasy X Official Strategy Guide

Shiva
Shiva is found in Macalania temple. This ice-based summon spell has a long history across the Final Fantasy franchise.

Shiva's Fayth is a female wearing a cloak over her head. As an ice being, Shiva is auto-equipped with the Ice Eater ability, letting her add ice damage to her HP when damaged. Fire spells do extra damage to her.

Her Aeon attack is Heavenly Strike, and Diamond Dust is her Overdrive.

Heavenly Strike
Shiva drops a large chunk of ice on an opponent's head. This attack has the potential to delay the enemies attack. This outcome is only sporadic against more powerful enemies, but does succeed occasionally.

Diamond Dust
Shiva casts an icy plain across all enemies inflicting elemental ice damage(believe it or not). She then snaps her fingers in order to shatter the icy plain to a sea of icy shards, Leaving Diamond Dust an aptly named overdrive.

Bahamut
Bahamut is one of the most powerful Aeons in the game. He is the strongest that you obtain as part of the story, and can do over 9999 damage when you acquire him.

Yojimbo
Yojimbo is one of the three optional powerful aeons. He initially has a strong evasion level but lower than average health and defenses. You have to pay an amount of Gil for him to attack.

He will choose one of four attacks:
 * Daigoro, a weak dog attack.
 * Kozuka, throwing three daggers at the enemy for medium damage.
 * Wakizashi, a powerful katana attack that will either hit one or all enemies.
 * Zanmato, an infallible 1-hit-kill attack.

The attack chosen will depend on the game's evaluation of a sophisticated motivation function that depends on the Yojimbo-resistance level of the opponent, Gil payed relative to Gil wealth, a hidden compatibility level, whether or not Yojimbo is in overdrive,  and a random number generator.

Yojimbo's attacks are automatically Penetrating. You cannot teach him any abilities. His Overdrive is only increase probability of using Zanmato.

Anima
Anima is Seymour's aeon. You can see it in a scene after the blitzball game in Luca, and you fight it in Macalania. However, you can also get this powerful aeon to fight for you.

Obtaining Anima
The details of how to obtain Anima are found on the Baaj Temple page.

Attacks
Her special attack is "Pain". This attack inflicts damage and Death to the opponent. The first time you see Anima is after the Blitzball game that you get to play at Luca when all the fiends start attacking. That is also the first time you see "Pain".

Her Overdrive is "Oblivion". Oblivion is when Anima takes you into oblivion (hence the name). Inside Oblivion, she breaks the chains that ties her hands down. It delivers hit after hit. This means that you don't need Break Damage Limit to inflict a lot of damage with this Overdrive.

When you first get her, she comes with all elemental Black Magic spells, plus Bio and Death. She also comes with a lot of status inflicting attacks, including Zombie Attack.

Magus Sisters
To obtain the Magus Sisters, the two seals in front of the door to the chamber of the fayth in Remiem Temple must be broken by using the Flower Sceptre and Blossom Crown. The Flower Sceptre can be obtained by defeating the first five of Belgemine's aeons (up to and including Bahamut), who conveniently stands in the middle of Remiem. The Blossom Crown is awarded at the Monster Arena for capturing at least one of every fiend from ../Mt. Gagazet/.

After getting the two items, approach the chamber of the fayth at the back of Remiem temple to break the seals and get your three new aeons, Cindy, Sandy and Mindy. You can enter the chamber again to receive a luck sphere.

In general, the Magus Sisters will have the highest stats of all the aeons (particularly Sandy's strength and Cindy's HP), and as all three fight at once will be a good choice for tackling the monster arena at lower levels. The catch is that you can't directly control the aeon's actions, but only really 'advise' them i.e. choose whether to attack, cast offensive magic, support magic and so on.

Sandy's Razzia is her special attack that does about 1.5 times normal attack damage. Cindy's Camisade is her special attack that does about 1.5 times normal attack damage. Mindy's Passado is her special attack that attacks at 10% power 15 times to give 1.5 times normal attack damage, however as a multi attack the damage can be significantly increased if your normal attacks would be over 99999 and if you have a high luck stat (causing critical hits).

Their overdrive is "Delta Attack", which hits six times for high damage (based on your magic stats). It is performed by selecting "Combine Powers" when all three sisters' overdrive bars are full.