Abel's Ark
From Xenosaga Wiki
Abel's Ark is a star system-sized object that appeared upon the crucifixion of the Messiah on Lost Jerusalem. The Galaxy Federation perceives it to be a giant Gnosis; however, it is actually one of the "eyes of U-DO"; U-DO's observational terminal in this dimension (along with Abel, U-DO's human form). According to the Episode III database, it has the power to change its perceived shape based on circumstances, and it only serves as an observer.
It is the form of Abel's consciousness manifested in real space (similar to the Testaments). The real space and the imaginary space are two planes of existence interwoven with each other in the Xenosaga universe. Real space is the plane of existence consisting of physical being and flesh, while imaginary space consists of consciousness. As the Ark is from the Imaginary Domain, it does not exist physically. Abel's Ark is the form of Abel's consciousness while Abel is the form of U-DO's physical being. They are referred to as "U-DO's eyes" because U-DO exists outside of the universe (the "Higher Domain"). Abel's Ark and Abel are the way those within our universe (the "Lower Domain") perceive U-DO's observation.
Originally, Wilhelm orchestrated the Miltian Conflict to force Shion to summon Abel's Ark; however, the power of Shion was not enough, so Wilhelm called on the power of Albedo and his lust to join U-DO, which caused Abel's Ark to appear in normal space. The Ark then seized the Zohar to better observe the Lower Domain, since the Zohar serves as the doorway between the Domains. However, in order to keep Abel's Ark in this dimension, Wilhelm needed to call on the power of Shion once again; he reconstructed the Miltian Conflict in Shion's subconscious, causing the fear of both young and old Shion to summon the Ark permanently in this dimension; the old Miltian Conflict did not cause enough suffering and disturbance, so Wilhelm needed to amplify the effect. His reason for summoning Abel's Ark was so that he could seal it away with Abel; this would allow him to use Zarathustra without the interference of U-DO (the Higher Domain's "God") upon human consciousness (this is because U-DO's observation distresses human consciousness, causing it to go out of control.)
Its primary shape resembles a crystalline tree or chandelier. The database claims that the ringed object in the center of its structure is not a planet, but an energy field. In Episode III, once Dimitri Yuriev travels to it, it reshapes into a flattened sword or cross. This secondary form resembles the Eldridge from Xenogears.
