Origin/Powers and Abilities
As a Saint, Ikki possesses superhuman strength, speed, and endurance, as well as extremely high defense granted to him by his Cloth. In terms of pure power, Ikki is stronger than any other Bronze Saint. His Houou Genma Ken attack (Demon Illusion Fist, later Phoenix Illusion Fist) is capable of completely destroying an enemy's psyche by forcing them to experience terrifying illusions or past memories, or can even allow Ikki to read their mind. His Ho Yoku Ten Sho (Flaming Phoenix Wings Rise) does more damage than even Pegasus' (the main protagonist) ultimate attack, the Ryu Sei Ken. His powers attributed to the Phoenix Cloth make him arguably stronger than even the Gold Saints. He can return from death unaided, and his Cloth is the only one capable of repairing itself, even after it has been completely obliterated. Each time he comes back to life, he becomes more powerful.
Ikki is the older brother of Andromeda Shun. When Shun was going to be sent to the legendary Death Queen Island, Ikki went in his place to protect him. His master on Death Queen Island, Guilty, tried to get Ikki to become more powerful by unleashing his rage. Guilty killed Ikki's friend Esmeralda, and Ikki retaliated by killing Guilty and finally winning the Phoenix Cloth. It is at this point that Ikki decides to take revenge on everyone who wronged him, particularly his father Mitsumasa Kido, the man who gathered the 100 young boys to train as Saints. Because of his training, Ikki's Cosmo is different from that of any other Saint--it is a special rage Cosmo.
Major Story Arcs
Galaxian Wars and the Twelve Temples
Ikki first appears in the story as a villain, showing up at the Galaxian Wars tournament to steal the Gold Cloth of Sagittarius. He led the Black Saints, a group of fighters led by renegade Saints with powers similar to those of Seiya, Shiryu, Hyoga, and Shun. When the Black Saints were defeated, Ikki faced the other Bronzes by himself. He was vastly more powerful than any of them, and appeared to have won, when the Sagittarius Cloth protected Seiya and helped him beat Ikki. In his last moments, Ikki regained his lost sense of self and apologized to his brother, but was crushed by a giant landslide.
Ikki was later reborn of fire during a fight between Shun and a Silver Saint. After that he fought alongside the other Bronzes on occasion, though he was very standoffish and preferred to work alone. During the Bronze Saints' siege of the Twelve Temples, Ikki psychically intervened to defend Shun from the Gemini Saint's assault. He later sacrificed himself to kill Virgo Shaka, having survived Shaka's Tenbu Horin "Dancing Dharma Wheel," which had deprived him of his five senses. Impressed by his strength and determination, Shaka brought them both back from the dead so that Ikki could save Seiya from being killed by Gemini Saga.
War on Poseidon
During the Poseidon saga, Ikki first appeared during the Bronze Saints' confrontation with the Marine General Lyumnades Kaza. Kaza had defeated Pegasus and Cygnus by taking the form of people they cared about. When he was about to kill Andromeda by taking the form of Phoenix, the real Ikki appeared to challenge him. Despite the fact that Kaza changed his form to look like his brother Shun, Ikki quickly defeated him, but wondered if things would have been different if Kaza had taken the form of Esmeralda. Ikki left the other Bronzes behind, saying that if they could not be ruthless on the battlefield, they did not deserve to be Saints.
When Ikki attempted to enter Poseidon's temple, he was stopped by Sea Dragon Kanon. Aware of Ikki's ability to return from the dead, Kanon transported him to another dimension. Ikki returned anyway, and Kanon used his ultimate technique, Galaxian Explosion. Kanon revealed that it had been he who had awakened Poseidon, and when it seemed that he had the upper hand over Ikki, Siren Sorrento appeared, not wanting to help Ikki but determined to put an end to Sea Dragon's ambition. With the last of the Marine Generals out of action, Ikki met up with the other Bronze Saints, who had recovered from Lyumnades' attack, to deal with Poseidon.
At the beginning of the Hades chapter, Ikki showed up at Sanctuary only long enough to tell the others that he did not intend to ally himself with them. Ikki did not appear in the Underworld until the reformed Gemini Kanon was cornered by the three Judges. Enraged upon finding out that Shun had been possessed by Hades, Ikki quickly dispatched of Garuda Aiacos and headed off to confront Hades. Ikki was gravely injured by the combined assaults of Hades and Pandora. With the last of his strength, Shun took control of his body long enough to give Ikki the chance to strike, but Ikki was not able to kill his brother, even for the sake of defeating Hades. Hades killed Ikki and had him buried in Cocytus.
When Ikki revived, he went through the Wailing Wall and was about to enter the Superdimension when Pandora stopped him. She asked that he avenge her for what Thanatos and Hypnos had done, and gave him her protective rosary so that he could cross the Superdimension unharmed, as his Cloth had not been reborn by the blood of Athena. Without the rosary, Pandora died, and Ikki agreed to carry out her wish. The Phoenix Cloth grew wings, enabling Ikki to fly through the Superdimension to Elysium.
During the fight against Thanatos, the Bronze Saints' Cloths were destroyed. When the Gold Cloths came to aid them, Ikki donned the Leo Cloth, having been born under the Leo constellation. The Leo Cloth was also destroyed, but upon raising his Cosmo to the limit and coming into contact with Athena's blood, Ikki obtained the Phoenix God Cloth. Ikki advanced with Seiya toward the tomb that held Hades' body, and the Saints eventually defeated him with the help of Athena.