Oa

Oa is a planet that lies in the center of the universe and occupied to a race of blue-skinned powerful humanoids who have dubbed themselves the Guardians of the Universe. Oa's history is not clear; according to some stories, the Guardians originated in a planet called Maltus. These evolved Maltusians later moved to Oa and named themselves Oans. Oa became a convenient base of operations. Other stories had the Oans living there from the beginning.