Poseidon is the Olympian god of the seas, earthquakes, horses and is the King of Atlantis. One of Zeus' two brothers, he participated in the Titanomachy and later the Second Titanomachy when Kratos sought to overthrow the gods of Olympus. Though he fought hard against the titans and his nephew, he was ultimately killed by Kratos.
Powers and Stats
Tier: At least 5-C, likely Low 5-B
Name: Poseidon, King of the Seas, Earth-Shaker, Father of Horses, Ruler of Atlantis
Origin: God of War
Age: Several thousand years at least.
Classification: Olympian God, God of the Seas and Earthquakes, King of Atlantis
Powers and Abilities: Superhuman Physical Characteristics, Flight, Weather Manipulation, Water Manipulation, Electricity Manipulation, Ice Manipulation, Immortality (Types 1, 3 & 4), Power Bestowal, Shapeshifting, Regeneration (At least Low-Mid), Teleportation, Astral Projection, Statistics Amplification when in or near water, Hippocampi Control
Speed: Massively Hypersonic (Could keep pace with Kratos)
Lifting Strength: Class E
Striking Strength: Class XJ (On par with Kratos)
Durability: At least Moon level, likely Small Planet level (Was severely beaten in his fight with Kratos)
Range: Standard melee range, several hundred meters to several kilometers with ranged attacks.
Standard Equipment: His trident.
Intelligence: High, though was affected by the evil of Anger after Kratos opened Pandora's Box, becoming easily enraged and irrational.
Weaknesses: Weapons of divine origin such as the Blade of Olympus can cause him harm or even kill him. Other gods or titans could possibly kill him as well. Being away from water can weaken his abilities.