A scholar at the Magic Academy who researches and develops magic technologies. He is a young genius at the Magic Academy which gathers knowledge from all of the continent in various fields. His knowledge of magical technology is second to none. He researched a way to fly in the sky in order to reach his mother, who is a Featherian. The Featherians live on a floating island in the sky.
Unfortunately most of his magical devices, even though they are successful, are declined from the Magic Academy staff for being possibly too dangerous for the public. He doesn't mind this though, since he does science for his own enjoyment. He gives the money he receives from his research to the villagers of his hometown.
He is a kind and intelligent person who doesn't show off his talent; because of that he is admired and popular in his hometown, Bronue. He is the son of the village's manager; this village is a humble farming village. His father's actions and ideals were full of humanism and positive thinking, and they greatly influenced Ariost. He is inspired to keep working hard even if no immediate rewards are given.
Carmaine met him at the cape west of Rosaria. Ariost was staying there for a short while. Carmaine's party sought Ariost's help to reach the Featherians when they needed a cure for Sandra when she was poisoned by the masked knights. They found Ariost in the ruins near the Magic Academy and rescued him from monsters attacking him. With the propeller he found in the ruins, he completed his flying device successfully. With this he took Louise to Featherland, however the queen Stella did not allow him to see his mother Gina.
He was finally able to meet his mother Gina at Featherland later when Carmaine's party was summoned by Stella, the Featherian Queen, to tell them about Venzern and the Space-Time Control Tower. They consulted with Gina as she had further information about the Power Stone.
He became a professor at the Magic Academy. He is the originator of several amazing inventions and he helped unite the humans and Featherians.
Wein Cruz brought the remains of an armored sand golem to the Magic Academy for analysis. Ariost investigated it and found that it reacted to a certain magical frequency and was controlled by someone remotely. He wanted to test his theory and produced a neural device that could remotely control the armor with his mind. It was risky however because if the remote body was destroyed, the controller would lose control of his own body and die. He gave the neural device to Wein.
Later Wein's party came to him again to find a way to track the people controlling the neural armors. Ariost suggested a detector device, but needed Wein to fetch a certain part to build it. The part was an antenna and would be in the Growsian ruins north of the Magic Academy. Wein found the antenna and gave it to Ariost to build the Neural Wave Radar. With this they could track down magic transmission signals.