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Ayn is the son of Rhys and Maia. After his parents married and Rhys abandoned his ties to his homeland of Landen, they became king and queen of Cille. Ayn was born and raised there as the crown prince. As a child, he had little contact with his relatives in neighboring Shusoran. His was a peaceful life until the age of 15, when the two cities were attacked by armies of cyborgs. King Rhys charged Ayn with a quest: find the legendary world of piece called Satellite. Wren and Mieu were his companions as he set out from Cille.
Their first stop on the quest was Shusoran, where Ayn visited King Lyle and Princess Thea. The trio continued on to a nearby town, where they were informed that Shusoran and Cille had been attacked again. A quick trip back home revealed both cities to be abandoned and overrun with cyborgs. The few survivors had fled to Aridia's cavern, where Rhys had met Wren years before. After arriving at the cavern, Ayn learned Thea had been captured. Lyle, gravely injured, asked Ayn to rescue Thea.
After rescuing Thea from another cyborg infested castle, Ayn and the group, now including Thea, traveled to Landen. They found Lena's daughter, Sari, as the current ruler. After a cold reception and a battle, Sari joined the group. She agreed to allow Ayn use of a treasure of Landen, but also wanted discover his plans. She was distrustful of Ayn, due to his father's perceived betrayal of her homeland.
With the final distraction out of the way, Ayn and his companions set out to finally locate Satellite. Along the way, they met Lyle again, who passed away shortly after helping the group cross to a different continent. From nearby Techna, the group boarded a shuttle that would take them to Satellite. During this trip, the true nature of Alisa III as a spaceship was rediscovered. Although the people of Techna and other areas may have known this, the knowledge had been lost in Cille and Landen, as well as their neighboring territories.
On finally reaching Satellite, it was also revealed to be a spaceship, this one travelling with Alisa III. Also discovered was Siren, a general of Orakio's armies, who had been sealed on the moon for approximately one thousand years. After a fierce battle, Siren was ousted from Satellite. The survivors of Cille and Shusoran moved there, claiming the spaceship as their home. Ayn (and the player) was given the option to choose either Thea, former princess of Shusoran, or Sari, queen of Landen, for a bride.
If Ayn chose to marry his second cousin Thea, the couple become king and queen of Satellite. They enjoy a time of peace and prosperity until Satellite is destroyed. The couple choose to remain and die with the ship, rather than evacuate. They have one child, Sean, who is evacuated and the sole survivor of Satellite.
However, if Ayn chooses Sari, he is welcomed to Landen as her husband. As king and queen of Landen, which now includes the lands of Satera, they raise one son, Crys. For twenty years, they repel many attacks, often by the forces of Lune. In this scenario, Ayn lives a longer life, but his later years are not chronicled.