Past[]
Gigantomachy[]
Poseidon meets with the other Greek Gods to discuss the strategy to be adopted during the Gigantomachy
After Zeus won the Titanomachy Tournament, he became the Chief God of the Greek Pantheon in Kronos' place. The Primordial Goddess, Gaia, refused to accept that outcome and led her own spawn, the Giants, in all-out war with the Greek Gods. This event would be known as the Gigantomachy. As the battle raged on, Poseidon met up with his brothers in Olympus Palace to discuss what to do, along with Hermes and Ares. Hermes reported the situation was unfavorable for them and Adamas took this chance to mockingly address Zeus as their Chief God, wondering what he'll do.
Poseidon watches Hades leave after learning that the Titans have broken free from Tartarus
Poseidon stayed silent, along with Hades. Zeus simply decided on pummelling the enemy and headed out for battle. The brothers then began going through their seperate exits. However, Poseidon noticed a soldier of Hades appeared and was telling him something. When Hades began walking away, Poseidon asked him what was wrong but Hades insisted he should pay him no heed. Poseidon then joined the rest of the Greek Gods in the battle against the Giants, which resulted in their victory. While the other Greek Gods cheered, Poseidon couldn't find Hades.
Poseidon reaches Hades to give him a hand against the Titans
He then approached the soldier that he saw with Hades earlier and asked him where his brother was. Bowing, the soldier admitted to Poseidon that Hades went down into Helheim all alone to stop the Titans, who had broken out of Tartarus. Worried, Poseidon went into Helheim and came the sight of Hades sitting on top of a broken column, whistling to himself, with the corpses of many Titans strewn about. Hades stopped whistling when he saw Poseidon and guessed they won if he's here. Poseidon criticised Hades for being far too reckless by sending all his men to assist them and running off alone. Hades said he only did what was right as the elder brother by watching over the backs of his younger brothers.
Poseidon tells Hades that he will not thank him, however calling him "brother"
Poseidon brought up the fact that he could've been defeated but Hades said he won't be. He vowed to Poseidon that he will not lose to anyone since, as the elder brother, he shan't be defeated. As Poseidon stayed silent, Hades fell on his back and supposed he was a bit too reckless this time around. Going up the column, Poseidon insisted he would not thank Hades before offering his hand. Uncharacteristically smiling, Poseidon called Hades "Brother". Hades then took his hand as he noted that this was the first time Poseidon ever called him that.
Adamas' Betrayal[]
Poseidon mortally wounds Adamas for having betrayed all the precepts of the Gods
When Adamas attempted to overthrow Zeus, Poseidon effortlessly slew him and erased his memory from history. Hermes, who witnessed the incident, started a rumor that there was a traitor among the Greek Gods. Only a handful of Gods know about the incident and why Adamas was removed from history. It was stated by Hermes that Poseidon could have killed Adamas if he truly wanted to. The remains of Adamas were recovered by Hermes on Hades' orders and sent them to Beelzebub, who gave him a robotic body.
2000 B.C. Gods' Council[]
Poseidon attends the 4000 years old Gods' Council to decide whether to let Humanity survive or exterminate it
Around 4000 years ago, Poseidon was present in the Gods' Council to decide the fate of Humanity. In the end, Humans were allowed to live but not without punishment, which was the destruction of the ancient Greek city of Thebes.
Ragnarok[]
Following the proclamation of Ragnarok, the challenge between Gods and Humans for the salvation of Humanity, Poseidon is included among the 13 fighters of the Gods.
Third Round[]
Poseidon enters the arena for the Third Round splitting the sea in two
Poseidon fights in the Third Round for the Gods against Kojiro Sasaki, and enters the ring dividing the waters in two. For a short time since the start of the match, Kojiro scanned Poseidon and wasn't able to find any way to attack him without being killed. Kojiro then sat down saying that he didn't want to die, surprising everyone in the audience. After some thought, the swordsman humbly asked Poseidon to demonstrate his technique, in hopes of gathering more information about the sea god's movements.
Poseidon avoids Kojiro Sasaki's Tsubame Gaeshi
However, Poseidon did not even acknowledge Kojiro's presense. Despite not seeing any way to survive even the first exchange, Kojiro decided to attack, opening with his best move, Tsubame Gaeshi. Initially Poseidon dodges it, but is surprised by the return of the attack and narrowly dodges it, with only a strand of hair being cut off. This angered the god of the seas, looking his opponent in the eye for the first time, and he started advancing on his opponent, which was so rare that it shocked the gods.
Poseidon wounds Kojiro Sasaki in the side
Poseidon used Amphitrite, a rapid series of thrusts with his trident, but Kojiro dodged every thrust thanks to his ability to scan and predict his opponent's moves. The sea god then began to whistle and started adding a little more strength to his attacks. Kojiro was unable to react in time and received a wound on the left side of his abdomen. Kojiro stumbled in pain, as Poseidon taunted him with a devious grin plastered across the usually emotionless god's face.
Poseidon looks badly at the Gods who are cheering for him
The gods in the audience erupted in cheers for their representative, but Poseidon stared them down, forcing the arena to fall silent. Kojiro asked why he does not accept support from his fellow gods, to which Poseidon replied that supporters are unnecessary to those who have attained perfection, and that gods are beings that do not require such things. Kojiro was disappointed to hear this and called it a pretty sad existence. This remark filled the god of the seas with tranquil fury, and he attacked Kojiro with Chione Tyro Demeter.
Poseidon breaking Kojiro Sasaki's blade
Kojiro continued to learn to evade Poseidon's attacks as he observed them and later used Ganryu Ougi Torakiri when he found an opening for a counterattack, but his blade was immediately shattered by Poseidon's trident. Kojiro then picked up the broken half of the blade with his other hand and asked the god if he ever lost himself and trained until the sun rose, or if he ever cried tears of gratitude for those that made him stronger, or if he ever felt love towards his opponent in a fight to the death.
Poseidon watches as Kojiro Sasaki uses Re Völundr to create two swords from the destroyed one
Poseidon didn't respond. Apologising, he stated that he knew Poseidon never felt any of that. Kojiro said that the sword represents the history and the hearts of all swordsmen, and that he would never lose to someone who never considered the hopes and dreams of others. Poseidon looked at the swordsman dismissively, but as the human finished his speech, the two pieces of his broken sword emitted pillars of light and reformed into a katana and a kodachi, having performed a Re Völundr using the sword's broken halves.
Poseidon covered in wounds after a series of attacks by Kojiro Sasaki
Now using the Niten Ganryu Ougi, Kojiro offered to continue the fight. Despite the entire audience being amazed at the development, the god of the seas called Kojiro a worm, remaining completely unimpressed, and attacked him. Kojiro used the techniques of the swordsmen he fought against throughout his life to avoid all of Poseidon's attacks and promply counterattack, leaving Poseidon covered in wounds. Poseidon looked at his wounds, wiping blood off of them.
Poseidon bombs Kojiro Sasaki with the Medusa Alope Demeter
He used the blood to slick his hair back and smirked. He started to whistle again, finally getting serious. The god of the seas continued to increase the speed of his thrusts, inflicting more wounds on the swordsman, as if, in the face of Kojiro's masterful techniques, Poseidon was only interested in turning the battle into one of pure strength. Poseidon used Medusa Alope Demeter, instantly retaking the initiative. Poseidon continued his relentless assault, overwhelming Kojiro who was starting to near his limit and started to slow down.
Poseidon's arm and trident are cut by Kojiro Sasaki
However, due to the cheering of his friends and the rest of humanity, he found resolve to continue. Kojiro's scanning ability evolved further, allowing him to scan all of creation at once. He successfully defended against all of Poseidon's attacks and closed the distance with him by using extremely fast footwork. Kojiro counterattacked Poseidon's thrust with Soen Zanko Banjin Ryoran, cutting off the god's right arm and breaking his trident.
Poseidon is killed by Kojiro Sasaki and loses the Third Round
Wasting no time, Poseidon quickly grabbed his dismembered arm and broken trident with his left arm, but it too was sliced off. Having only his teeth left and refusing to give in, Poseidon furiously bit on his weapon's shaft and tried to stab Kojiro. Despite his best efforts, Kojiro finished him off with a cross slash across his abdomen. In his final moments, Poseidon angrily cursed at Kojiro as his torso fell to pieces and his lower body fell to the ground. He eventually disintegrated and was wiped from existence, marking the god's first loss.
Legacy[]
At some point after the Third Round, the remains of Poseidon's trident were collected by Proteus.
Zeus, Hermes and Ares are furious at Poseidon's defeat and want to avenge him by sending a Greek God in the Fourth Round
Unlike the other winners, Poseidon's death did not seem to have a profound impact on Kojiro, who was more affected by his first victory. However, this was the gods' first loss, and they realized just how dire the stakes of this tournament were. Zeus met with Ares, Hermes, Loki, and Shiva to discuss Poseidon's loss, with Shiva being infuriated that the gods lost. At first he volunteered himself, but Poseidon's loss had greatly angered Zeus as well as Ares and Hermes. To avenge Poseidon as well as to get the greeks a win back, Heracles was sent out as the fighter for the fourth Round.
Hades decides to replace Buddha as the fighter of the Gods in the Seventh Round to avenge his brother Poseidon
Once news of Poseidon's death reached Helheim, Hades came to Valhalla to watch Round 6, curious to see the circumstances that led to his brother's untimely death. Once it ended, and the gods had a vacant spot, Hades volunteered to fill it. When asked why he suddenly wanted to participate in Ragnarok, he said the he was fighting to avenge his brother. Proteus gave him Poseidon's trident as he made his entrance, which Hades took and combined with his own bident to fight alongside his fallen brother. During the match Hades often refers to his brother calling him the closest deity to a king he knows, and also intoning his whistle. In the end, however, Hades fails to avenge Poseidon and is killed by Qin Shi Huang at the end of the Seventh Round.
As with the other fallen participants of Ragnarok, Hermes composed a requeim for him.
A picture of Poseidon also appears in a shrine that Brunhilde visits after Round 8. In it, he represents "pride".