Klaus

Zanza, referred to by his venerators as Lord Zanza, is a main character and the true antagonist in Xenoblade Chronicles. He existed before the creation of the game's universe. Long before the events of the game, Zanza was a human named Klaus who was responsable of the destruction of his universe and the creation of the game's universe

Before the events of the Game
Zanza, originally called Klaus, was once a scientist working on a project attempting to create a new universe. His experiment was a complete success, as he wiped out the original universe and recreated it.Zanza and Meyneth were the only beings to survive the destruction, and emerged from the endless sea of the new universe as Bionis and Mechonis.Many years before the start of Xenoblade Chronicles, Zanza began to fear the day when his creations would leave him, considering it would mean his own demise since the God was feeding on them to survive.This, coupled with his growing loneliness and the fading of awareness of him among the denizens of Bionis, led Zanza to engineer a cycle of destruction and regeneration, in which all life must eventually be destroyed, returning to him to be recreated and Zanza possessed Arglas, a Giant from Bionis, who is confined by the High Entia on Prison Island after trying to destroy Mechonis and all of its inhabitants with the help of his three disciples: Dickson, Alvis and Lorithia. He reveals himself to be the creator of the Monado to Shulk and his party.

14 years before the events of the game, Zanza kill Shulk and his parents and use the body of the young Hom as a vessel to retrieve his power

Present day
When Shulk's group arrives at Prison Island, the Mechon launch an attack. Zanza, in Arglas' body, makes a deal with Shulk: he will unlock the Monado's true strength if he is released from his shackles. Shulk eventually agrees and releases Zanza. However, just as Zanza appears to be back at full strength, Metal Face arrives with Face Nemesis and a horde of Faced Mechon and impales him with an Ether-destroying spear developed by Egil and Vanea.Zanza's body is dead, but his consciousness remains and continues to talk to Shulk as they fight the mechon.

Although mentioned more than once, Zanza does not reappear in person until the events at the Mechonis Core when Shulk is shot in the back by Dickson, Zanza emerges from his body. He reveals his motives for possessing Shulk, as well his desire to endlessly destroy and regenerate all life, he defeats Egil and his Yaldabaoth as well as Meyneth herself who was inhabiting Fiora.Zanza then claims Meyneth's Monado and vanishes from the Core, teleporting to Prison Island. Here he causes it to sink inside the head of the Bionis, releasing copious amounts of ether and starting the process of turning the High Entia into Telethia. He uses the Bionis to attack the fleeing party, but Egil uses the Mechonis to defend them, and wounds the Bionis before he and the Mechonis are destroyed.

Once in space, the team meets Zanza in his second form, a cross between the Bionis and the Mechonis' bodies. He welcomes them, and thanks Shulk for his role in delivering the two Monados to him. Zanza offers Shulk the position of his new disciple, but Shulk turns him down. Zanza expresses regret that he must wipe out the Homs, as he had "a desire for friendship".

After this battle Alvis speaks to Zanza, informing him that even gods are restricted by providence. Zanza sees this as a betrayal and rebukes Alvis for disobeying him. Alvis asks Shulk to make a decision: "Does this world belong to Zanza? Or does it belong to you?" The Monado III gains a new symbol (神 (kanji for god/deity)), giving it the power to harm gods. Shulk use the Monado, and the god is finally destroyed.