Posdeidon is an immortal man with long blue hair, and a blue beard. His skin is tanned, and he has a strong brow and jawline. He wears flowing robes and a golden crown, and is surrounded by spirit power that resembles water and sea creatures.
Once a human cultivator wielding a Trident sea-type tool spirit, he gradually became strong and was worshiped by many sea spirit masters and sea spirit beasts during his travels among various islands and reaches of the Douluo Planet seas. During his travels, he helped many spirit masters and sea-type spirit beasts while ending many conflicts, thereby obtaining great belief from them that would allow him to evolve and advance to a True God, reaching the level of a 1st Class God. As a God, he became acquaintances with his successor Tang San's predecessor, a Great God King the Asura God.
At some point in the past, Poseidon blinded one of the eyes of the Deep Sea Demonic Whale King.
He is worshiped by denizens of the Nine Star Sea, notably on Sea God Island. Bo Saixi, his descendant, led the Sea God Temple for many years. He is attended by the Seven Children of the Sea God, a title given to the protectors of the Seven Pillars of Sea God Island.
Poseidon saves Tang San from the Deep Sea Demonic Whale King, threatening to blind his other eye if he didn't leave, but spared his life due to his slow cultivation speed. He expressed hope that Tang San wouldn't let him down, and vanished.