Oceanus is one of the titans that was imprisoned at the centre of a galaxy in the NeSiverse by the Twelve God-Monarchs who wanted to siphon his power for themselves. He was the father to Metis, who later married Zeus but then he betrayed and killed her by absorbing her into his mind. Eventually from Zeus' skull burst Metis' daughter and granddaughter to Oceanus, Athena.
The titans were created by the Primordial Deities Uranus and Gaia, Uranus representing reality and dimensions while Gaia was life. They then used the essences of their parents to continue the legacy of creation as they proceeded to create universes, galaxies and worlds across the Multiverse. They created other beings, including beings that would be considered deities. However the essence of Uranus, which was the structured and ordered nature of reality, railed against the unorganised and temperamental crafts of the titans. Urged on by the essence of Gaia, the bravest of the titans, Kronos, metaphorically slew Uranus and the nature of reality became fractured, creating dimensions, alternate realities and Realms with barriers separating them. Uranus, however, was not to be retired without a final say. He predicted that Kronos himself would, likewise, be overthrown by his own children. Kronos became paranoid. He and his sister, Rhea, had created many deities throughout the Multiverse and any of them could overthrow him. In his madness he ate his children - the deities he had created. He consumed them into himself where they remained trapped within an endless, cycling Narrative moment. The last of these gods, Rhea sought to hide from Kronos. Using Plotlines she was able to weave a Story for her son and hid him on a small, irrelevant world as an underdog hero - Earth. The deity would grow into the god known as Zeus[Leg 1].
Yet the conditions by which Zeus would overthrow his father became indirect. It was through him that the Twelve God-Monarchs were able to pinpoint the titans at the creation of the NeSiverse - in which Zeus had been stashed. He told them of his father's weaknesses, strengths and armed with the knowledge of the son, the deities from the future were able to imprison the titans, including Oceanus. In return, the God-Monarchs freed all of the deities that Kronos had consumed. Many of these deities, thankful to their saviours, would come to serve or even worship the God-Monarchs. Zeus thus created a blade and imbued it with the essence of his great betrayal against his father - the legendary sword Harpē that would fall into the hands of various human heroes of Earth throughout the lifetime of humanity[Leg 1].
Zeus married another deity, who had been the daughter of Oceanus and not Kronos - therefore never swallowed. She, Metis, was already a god of the Naacal people who existed long before the humanity of Zeus. She was one child of three thousand siblings that were scattered across the Multiverse and were all deities of ocean-bound peoples. When she became pregnant, however, Zeus was struck by a prophecy - he would be overthrown by child born of Metis. Harkening to the overthrown of Uranus and the overthrow of Kronos, Zeus was, like his forebears, determined to defy this destiny. While still wielding Harpē, the sword and symbol of betrayal, he battled against his beloved wife. He was able to defeat her, but rather than slay her he consumed her essence into his own mind. There she continued to exist, deep within his thoughts[Leg 1].
Even while Zeus had remarried, to his sister Hera, Metis worked within Zeus' mind to create armour and weapons for their unborn child. The incessant pounding and hammering drove Zeus almost to the point of insanity. He sought his son, by Hera, Hephaestus - the god of blacksmithing. Hephaestus was to create a hammer and with that hammer he would hammer open the head of Zeus. Hephaestus was horrified, but eager to work on such a complex and unusual item. With that weapon in hand, Hephaestus cracked his father's skull open. From within emerged the child of Metis and Zeus, grown and fully armoured. The powerful, spirited, wise and brave Athena was born. Despite the prophecy, Zeus was excited to meet this new daughter and welcomed her to Mount Olympus[Leg 1].