Uni is the leader of the Epsilon Clan and the guardian of all Elemental Angels. She is a seraphim and has the ability to take new powers as her own.
Power: Adaptive Mimicry
Profession: Judge of Souls / Guardian of Elemental Angels
Celestial Race: Seraphim Division
Hair: Mauve / Pink
Skin: Light Brown
In Volume 1, when Venus asks Hyperion who Uni is she refers to her as the "Creator of us all". However, in Volume 6, Uni refers to God as if God is something above her and independent of her. So Uni is the creator of all the living beings, but she is not the God of the universe. Uni and her husband, Tin, can be thought of as a celestial Adam and Eve.
They are the first male and female angel and thus all other creatures are descendants of theirs or creation of theirs. They do have three daughters, Aurora who is in the Sigma Clan; Hyperion and Hercleo from which the Lambda Clan are descendents. All of their creations were given free will by God and thus given the choice to become good or evil. It is Uni and Tin's job to keep the balance of good and evil and make sure that evil does not over step its boundaries.
In the Elemental Angel series it is common for angels to also have the power over creation such as Luna the Moon Angel and Sakumo the Angel of Strength. It does not, however, make them a god or goddess. By definition they could be considered as such, but all the benevolent immortal beings are referred to as angels not deities.