Seymour (Final Fantasy X boss)

The first battle with Seymour Guado occurs shortly after Yuna receives her fourth Aeon at Macalania Temple. Tidus and the other Guardians had discovered Seymour's treachery in murdering his father and attempted to stop him.

At the start of the battle, Yuna, Tidus and Wakka can talk to Seymour using the Trigger Commands. Doing this will raise Tidus' Strength and Yuna and Wakka's Magic Defense. Seymour is flanked by two Guado Guards who will use Hi-Potions whenever they are hit with a physical attack. Using Rikku to steal these from them will prevent this action. The second of the two to be eliminated will cast Protect on Seymour, who will then cast Shell on himself.

Seymour will cast spells at the active party in the following order: Blizzard, Thunder, Water, and Fire. Using Yuna's Nul spells will help negate any damage.

After his HP drops to 3,000, Seymour will summon his Dark Aeon, Anima.

Anima
When Anima appears, take Tidus' advice and summon Shiva. Defend against Anima's Pain and heal using the Ice spells until Shiva has a full overdrive gauge. Diamond Dust will potentially do near max damage to Anima. From then, keep Shiva alive until Anima unleashes Oblivion and then just attack until she is dismissed by Seymour. If Yuna can use Grand Summon and call Shiva with a full overdrive gauge at the start, this part of the battle will go much quicker.

After Anima is defeated, Seymour will have returned to full health and his Magic power will be raised. Using Auron's Magic Break will reduce the effect of the spells. Seymour will now vary his spells and will also cast twice in one turn, however by using the Nul spells and attacking with the two best fighters, the battle is sure to end in the party's favor.