Seymour Flux

The third battle with Seymour, in his Seymour Flux form, occurs after Yuna and her guardians make their way up Mt. Gagazet to get to Zanarkand. He is known as "Seymour Beta" in the Spanish and Italian versions.

Battle
Seymour summons a seemingly robotic being, called Mortiorchis, upon which he sits. As with previous Seymour battles, certain party members may use the Trigger Command to talk to him. For this battle, Kimahri can talk to Seymour to raise his Strength, and Yuna can talk to him to raise her Magic Defense. This battle is notorious among fans as being among the hardest non-optional bosses in the game, due to Seymour's powerful attacks and his signature attack, Total Annihilation.

Seymour Flux can use the attack Lance of Atrophy to put an ally into Zombie status, and the Mortiorchis will combo with Full-Life, effectively KO'ing a character (unless the characters have high Agility, as well as many Holy Waters). Like Seymour Natus, he can also Banish an aeon, giving it approximately one turn to attack if summoned. Seymour Flux occasionally casts Protect and Reflect upon himself.

Three turns in, Mortiorchis will start to use Cross Cleave, which deals around 2,000 damage to the whole party. Seymour will then cast Reflect on himself and rebound Flare at a party member, but a character with high Agility or in Haste may get a turn in between and can Dispel Seymour, causing him to cast the spell on himself.

Total Annihilation is Seymour Flux's signature attack, as well as his deadliest, which requires three rounds of charging, and will kill anything but an extremely good party. It is recommended to cast Shell on all high-HP characters and then defend if possible before he executes this. It may be necessary to sacrifice an aeon to survive.

Strategy
Seymour is vulnerable to the poison status (the Mortiorchis is immune), and if Lulu casts Bio on him, he will take 1,400 damage at the end of each of his turns (sometimes, he will get two turns in a row not long before Mortiochis, so he'll use Lance of Atrophy on his first turn then skip the second, thus he will react to damage twice just a second apart); this will whittle down his health without, potentially, any other actions.

To protect the party from Seymour's Lance of Atrophy, the player can either equip them with Blessed armor (which can be bought from Wantz on the mountain, or can be made by customizing a piece of armor with Holy Water), or use Holy Water on the afflicted character before Seymour can cast Full-Life. Armor customized to give Auto-Med (in this case, requiring a small stock of Holy Water) is useful for this.

Quickly dispelling Seymour's Reflect when he casts it on himself will prevent him from bouncing Flare on his next turn.

Seymour is immune to all Breaks, and has greater Magic Defense and physical Defense than the average enemy. Magic, such as the White Magic Holy, or the Black Magic Flare, should still do considerable damage, due to their high base values. Characters with high Strength or Magic will still do decent damage, no matter the type of attack. Since the Piercing ability can penetrate his Defense, Piercing physical attacks will do relatively more damage than magical or regular physical attacks.

Hastega, and aeons prepped to have full Overdrive gauges, are a big help as usual. The aeons will have only one or a few turns before they are banished by Seymour. Shiva's Diamond Dust does quite high damage to all targets, and Bahamut's Mega Flare is capable of breaking the damage limit. A very good strategy should be casting Bio, as mentioned above and then summoning any aeon except for Bahamut. This method will do if any four aeons have overdrives. If all five have overdrives, then there is no need of Yuna's overdrive. If four of them have it, then the player can Grand Summon the aeon which doesn't have its overdrive.

Mixing two Underdog's Secrets (99 of them can be obtained from Rin in Fahrenheit if the player has learned all the Al Bhed language), is also capable of breaking the damage limit.

Related enemies

 * Mortiorchis
 * Seymour
 * Seymour Natus
 * Seymour Omnis