Ergo Proxy

The powerful and mysterious Proxy appearing before Re-l at the beginning of the series, subsequently thrashing Re-l's apartment in his fight against Monad.

Ergo appears many times throughout the story, and eventually, the secret of his identity is revealed.

[Spoiler] Ergo Proxy was the creator of Romdeau Dome city as well as dozens of its citizens. Ergo was an imperfect god and thus his creations were imperfect. In despair, he entrusted everything to a man named Donov Mayer, and left the city to join with Monad, the Proxy of Mosque. [/Spoiler]