Caliburn's Altar is the throne containing the Caliburn.
Caliburn is the source which was created by all the Deities to keep the world out of balance. It was then protected by the Partholon's weapon, Ouroboros, to keep it out of the wrong hands.
It is now time to go retrieve it to drive out Cichol and the remaining Fomorians. Shadow encounters the Ouroboros which is defeated shortly, but Cichol appears trying to take the Caliburn to destroy Erinn. In response, the Caliburn ties down Cichol's power, and a blade is generated from the Altar which directly stabs Cichol, killing him.
Shadow is rewarded the Brionac, the Spear of Deities and the final transformation of Caliburn. Morrighan appears shortly, warning him about the dangers of how Light and Darkness are responding against the will of Twilight, growing stronger and more threatening.
Shadow: Its been years... I'm surprised this place hasn't changed... much.
(He walks forward, taking note of the Ouroboros Statue)
Shadow: Hmm... These haven't changed either...
(Immediately, the statue crumbles, and the snake heads are seen. All four of them groan, roar, and hiss towards Shadow)
(All four of the snake heads groan in pain, and Ouroboros collapses. All of them vanish in a flash of light)
Shadow: ... That wasn't much fun than before... Nor challenging...
(The Altar of Caliburn appears in the center. However, Cichol appears behind Shadow, and blasts him with his Chaos Burst, knocking him out of the way)
Cichol: Muhehehe... you did a fine job removing those four obstacles for me... Now the Caliburn will be mine! And all of Erinn will vanquish!
Shadow: Cichol! No!
(As Cichol tries to obtain the Caliburn, a white chain emits from it, and attaches itself to Cichol, holding him down)
Cichol: What the?!
(A spear emits from the Caliburn, and immediately rushes and stabs Cichol's heart, ultimately destroying him)
Cichol: Damn you Shadow... But this isn't over! In the future, I will have my revenge!
(Cichol's body vanishes, as the Caliburn is absorb by Shadow's pure heart, and the Brionac in his hand. Morrighan appears behind him)
Morrighan: Shadow, just a warning: Just because you have the Caliburn, the controls of Erinn, it doesn't mean you can rest. Darkness and Light are constantly growing stronger, and may even rebel against Caliburn. Good luck with maintaining the Twilight...