- Fragment of Invincibility
The War of Transgression that pitted Cocoon against Pulse took place 700 years before the catastrophe. The common wisdom on Cocoon is that the war was sparked by a Pulse invasion; however, Pulse records claim that the culprit was a 'demon from Cocoon.' Historians remain divided to this day.
The people of Pulse had always feared invasion from the sky, and made preparations accordingly. These included 'immortals,' war machines of immense strength and durability that were able to fight fal'Cie even when half-destroyed. The ancient weapons where designed for a defensive war on the ground, not offensive airborne assaults. Some historians claim that this proves it was Cocoon that instigated the war.
The Immortal will start with Forge Blade to summon the Centaurion Blade. Centaurion will use Electrocute to deal major Lightning-based damage to the whole party and give the Centaurion Blade both Enthunder and Bravery. It is weak to Fire. If the Centaurion Blade is destroyed, the Immortal will create another.
It is recommended to start the battle with SYN/SYN/SYN to bestow as many buffs as possible before the Centaurion Blade appears.
When the Centaurion Blade appears, the party should change to RAV/COM/RAV having Serah and a monster in Ravager roles with Fire spells and Noel as Commando to deal damage. The aim is to destroy the Centaurion Blade since it cannot be provoked. Protection against Lightning is a great help. If Electrocute is used, the party should change to either MED/MED/MED or MED/MED/COM, where Noel is essential due to Curaja, with a Commando monster, and then attack until the Centaurion Blade falls.
Immediately after, the party should focus into attacking the Immortal who will only use weak physical attacks twice before using Forge Blade once more. With the paradigm mentioned above one can ensure the chain gauge is maximized and stabilized before the Immortal is successful on his summon. Noel being a Commando is important as at this point he should have Launch, which he will use giving the party time to use Ultima Arrow through Serah (if learned). In either case, the party should change to COM/COM/COM and change the leader to Noel to ensure maximum damage and use Meteor Javelin before the Immortal's chain gauge depletes, which can deal as much as 70,000 damage.