Marin de Águila

Marin appears attractive and well-proportioned. She has orange hair of medium length. Her true face is unknown.

Marin has demonstrated a brave and just personality, defending the weak. She is very harsh when teaching Seiya, but she also shows concern for him, as demonstrated when she helped him in the Royal Demon Roses' funeral procession. Like Seiya, she always dreamed of finding her lost younger brother. Because of this, some Silver Saints assumed they were the same brothers, who didn't recognize each other. She searched for her younger brother for years without success.

At the Sanctuary, she was Seiya's teacher, instructing him for six years through rigorous and deadly training, such as performing hundreds of sit-ups on the edge of a cliff. She explained to her disciple the concept of the Cosmo in the Saints and assigned him Pegasus as his guardian constellation. She observed how her student defeated Cassios in his final test to obtain the Pegasus Cloth and how he grew stronger by defeating Shaina of Ophiuchus and her henchmen, who wanted to avenge Seiya's victory over Cassios. Marin remains at the Sanctuary but Shaina does not sit idly by, she is training hard to get revenge. After a while Shaina wants to test her strength and in the process get revenge on Marin, so she prepares an ambush by getting a supposed training match. Shaina begins by testing Marin and although she manages to dodge, she cannot withstand the hand-to-hand combat and is forced to retreat, tired and panting. Shaina mocks her and makes her see that this is a real fight so Marin puts herself on guard but is knocked out with a simple Thunder Claw. Shaina fights without quarter and does not let Marin recover, she continues hitting her trying to paralyze her movements until she is completely at her mercy, then Shaina changes strategy and rushes at Marin using her fists that hit her even harder.

Shaina hits Marin hard, giving her a brutal beating. Marin can't react to such a devastating series of punches. Marin can't hold on much longer and begins to bleed profusely, but Aiolia quickly interrupts the fight, saving Marin.

She is sent by the Sanctuary along with other Silver Saints on a mission to assassinate the Bronze Saints who participated in the Galaxian Wars, a tournament that broke the law of the Saints by fighting for personal ambitions. She arrives in Japan accompanied by Misty of the Lizard, Moses of the Whale, Asterion of the Hound, and Babel of the Centaurus. While the Bronze Saints finish facing the Black Saints on Mount Fuji, Misty demolishes the mountain with a single blow, hoping to bury them alive. However, they are all teleported away with the help of Muu, all except Ikki of the Phoenix. Marin manages to realize this and warns her companions to search for their targets in the surrounding area. The Lizard Saint discovers that it was Muu's work and tries to assassinate him on the beach, but Marin stops him, as that was not his mission. When Pegasus Seiya awakens on that same beach, he is excited to see his teacher, but Misty intervenes, threatening to kill him, and demonstrates great superiority in a brief confrontation. Without Seiya being able to do anything, Marin, through an illusion, pretends to pierce her disciple's heart with her fist and kill him. The rest of the Silver Saints arrive believing they have killed the Bronze Saints, but in reality they are the Black Saints, disguised by Mu through another illusion. Considering their task complete, they bury the bodies on the beach and all the hitmen retreat except for Misty, who suspected the deception caused by Marin when she pretended to eliminate Seiya. When Marin, Moses and Asterion return, they discover that both Misty and Babel have been eliminated by Seiya and Hyoga of Cygnus respectively, due to the marks of attacks they left on their victims. In addition, they also verify that the buried corpses are the Black Saints, deducing that they have been completely deceived. Upon learning that Marin left her student alive, she is considered a traitor, so they attack her mercilessly until they knock her out.

The Eagle Saint was unable to compete with Asterion's mind-reading ability and Moses' great physical strength combined, resulting in her being chained to a wooden cross in the middle of the tide as bait to attract the Saint of Pegasus. Once Seiya returns, he defeats Moses, but Asterion manages to easily knock him out. In that time, Marin manages to awaken and free herself from her imprisonment. Facing Asterion once more, and keeping her mind empty in order to prevent it from being read by her rival, she surpasses his speed and strikes him several times with her leg, debuting her Eagle Toe Flash technique and defeating the Silver Saint. However, she decided to hold back so that he would stay alive and announce to the Pontiff everything that had happened, thus becoming an enemy of the Sanctuary. Marin disappears, leaving some words written in the sand for Seiya to read upon awakening: "SEIYA GUARD ATHENA". Marin, informed by June that Seiya and the other Bronze Saints have penetrated the twelve Houses, reappears at the Sanctuary to try to help Seiya, when he was in the Temple of Leo. When Marin separated from Seiya in Japan, she set out to unmask the Pontiff, and to do so, she decided to investigate the forbidden place to which only he is allowed access: Star Hill. At the altar located at the top of the mountain, she discovered the corpse of Pontiff Shion, who had been there for thirteen years. Knowing that the current Pontiff is an imposter and murderer, and covered in wounds from the difficulty of the climb, she goes to the Sanctuary to help Seiya.

When Seiya was unconscious on the road behind the Temple of the Two Fishes, Marin came to his aid and protected him from the funeral procession of the Royal Demon Roses by putting her mask on him, which works as a filter against the poisonous perfume of the roses, before collapsing, exhausted, trying to drag her student to the top. Seiya managed to regain consciousness and disperse all the roses with supersonic punches. With the path clear, Shaina of Ophiuchus appeared to take care of Marin. Once the Saint of Eagle awoke, she revealed to Shaina her expedition to Star Hill and the corpse she discovered there. She appeared with Seika, who had been missing for six years. She found her living in the village of Rodorio, near the Sanctuary, after losing her memory after falling off a cliff while searching for her younger brother Seiya. Finally, Marin is injured after protecting Seika with her body from the attacks of the God of Death Thanatos, who was trying to kill her to torment the Saint of Pegasus.

•Eagle Toe Flash: This is Marin's most powerful technique in Eagle. To execute it, Marin moves with astonishing speed and leaps vertically into the air. Once there, with his left leg forward and his foot extended, he plummets at speeds exceeding Mach 3 (1029 m/s) towards his opponent, delivering an aerial kick to the abdomen that inflicts devastating damage.