Zelos (also known as Jeros), is the Silver Gigas. The player first views the creation of the Silver Gigas in the Hall of Knowledge, where all the history of Arcadia is revealed.
In its final form, the Silver Gigas prepares to annihilate the world.
Birth and Role in Creation
Around a thousand years ago, the Elders used their creation to summon the Rains of Destruction upon the Old World, causing the genocide of all organisms except humans. Zelos was described by the Silvite Elders to have been created out of "nothingness". The Silver Gigas has the power to execute the Rains from the continent of Soltis. It was sealed by the Elders under the sky along with Soltis.
Ressurection
In the events of Skies of Arcadia, Galcian and Ramirez were able to use all six Moon Crystals stolen from Vyse in order to break the seal of Zelos' imprisonment. Galcian then commanded the Gigas to raise the ancient continent of Soltis from Deep Sky. As a demonstration of his power, Galcian called upon the Rains of Destruction to completely wipe out the Valuan Capital. Later, Ramirez initiated the last Rains as an attempt to avenge Galcian, targeting the whole of Arcadia. However, the Elders were able to bombard the Great Silver Shrine against the beam before it reached the Moons, and crush the Dome of Light. Ramirez is eventually defeated by Vyse and his party, so forth allowing Zelos to consume him and add himself to the Silver Gigas' power. Zelos is the last boss that the player will fight in a ship battle.
According to Fina, Zelos is based on Silver animals like Cupil, which takes on many forms. This Gigas has two forms. In its first form of a sphere, Zelos casts the strongest level of all six types of magic. It also unleashes the devastating 'Moon Ray'. Afterwards, Zelos will morph into the figure shown above, as it takes on damage. In this final form, the Gigas may use the 'Great Moon Ray', 'Judgement', or 'Moon Lament'. Progressing through the battle, Zelos will eventually begin to lose its "claws", one by one. If the player does not destroy the Silver Gigas before it loses all six of its claws, it will automatically self-destruct. This type of behavior is similar to that of the giant squid called Obispo, which eventually loses its tentacles. The Silver Gigas was destroyed by Vyse and his crew aboard the Delphinus. But an amalgamation of Zelos and Ramirez is left behind on the deck of the Delphinus for the final battle, and a final act of vengeance.