|Final Fantasy X Boss|
|シーモア:最終異体 (Shīmoa: Saishū Itai)|
|Địa Điểm||Garden of Pain|
|Steal Được||Shining Gem|
|Hiếm Steal Được||Supreme Gem|
|Thường Rơi||Lv. 3 Key Sphere|
|Hiếm Khi Rơi||Lv. 3 Key Sphere|
|Rơi Weapon||Piercing, Magic +20%|
|Rơi Armor||SOS Shell, SOS Protect, SOS Haste|
|Kháng Lại||Zanmato (Lv. 4)|
|Miễn Dịch||Silence, Sleep, Darkness, Poison, Petrification, Slow, Zombie, Power Break, Magic Break, Threaten, Death, Provoke, Doom, Distil, Gravity, Delay, Eject|
|Thông Tin Khác||Seymour Omnis's elemental affinities depend on the positioning of the Mortiphasms.|
- "I will learn to control it, from within. I have all the time in the world. Since you were gracious enough to dispose of Yunalesca...the only means of destroying Sin is forever gone. Now nothing can stop us!"
- — Seymour
The final battle with Maester Seymour Guado is staged within Sin, where Seymour has abandoned his plan of becoming Sin in favor of learning to control Sin in his megalomaniacal effort to purify Spira.
Seymour's form is similar to Natus, only transparent with a shimmering, inhuman glow. There are no tricks this time, no surprise special moves that Seymour will suddenly wipe out the party with. This is purely a magic battle, and Seymour is clearly dominant.
He is hovering in the air in front of four huge disks called Mortiphasms. As each disk rotates, a colored section will face the side closest to Seymour; these will determine which four level-three spells he will cast at the party each turn. If each color is the same, the spells will have increased power. Seymour's magical weakness is determined by whichever side is furthest away from him when he is attacking. After each attack, the disks will rotate so a new spell is used. As the disks are all facing the same way at the beginning of the battle, one of the first actions should be to forcibly rotate one by attacking it, this will prevent a barrage of very powerful spells being cast one after the other. Physically attacking a Mortiphasm will cause it to rotate to the left, and using magic will cause it to rotate to the right. However, the Mortiphasms, unlike Seymour, are out of reach, so only Wakka can attack them physically.
After six rounds, Seymour will begin casting multi-Dispel and then following with Ultima. With no way of reducing the damage, it can potentially do over 4,000 damage to all characters. By this point, Lulu should know Doublecast and Flare, and Yuna will have obtained Holy; they can all be used to great effect against Omnis.
An interesting way to handle this battle is to let your Aeons do the work; unless Seymour is using Water spells, summon the corresponding elemental Aeon (Ifrit if Seymour attacks with Fire, Shiva for Ice, and Ixion for Lightning). They will absorb the spells although their overdrives will not be very helpful unless they survive Ultima and Seymour changes elemental characteristics.
An Alternate Strategy is to have Auron use Armor Break on Seymour, then summon Anima in Overdrive mode and have her perform Oblivion, since Seymour has less than 99,999 HP, Oblivion will kill him in one hit. Because of his relatively low HP, a single hit from a high Strength character with a Break Damage Limit weapon will also kill him.
A final option involves casting reflect on all party members and continually attacking the discs physically so they never line up. In this way he never receives full immunity so every time he casts a spell it will bounce back. In this way you can almost sit back and pretty much watch him kill himself, which may occur even before he starts to cast harsher spells. Also remember to equip all party members with equipment which nullifies certain elements.
- "By all means, try! You should thank me. Your death means your father's life!"
- —Seymour to Tidus right before the fight begins.
- "You would oppose me as well? So be it."
- —Seymour to Anima if she is summoned during the fight.
- "But there is no salvation for the damned! Rest in peace, in eternal darkness!"
- —Seymour to the group before casting Dispel.
- "Death awaits you."
- —Seymour to the group before casting Dispel and Ultima.
- "Let darkness take you!"
- —Seymour to the party before casting Ultima.
- "So it is you, after all, who will send me. But even after I am gone, Spira's sorrow will prevail."
- —Seymour to Yuna after his final defeat.