Aion (アイオン) is the main boss in Chapter 18x: Imprisoner of Magic (Chapter 19x in Hector's Story). He is a member of the Black Fang, known as "The Owl", although he is not an original member and serves under Nergal directly as opposed to Brendan Reed.
A very arrogant man, Aion believes himself to have intelligence above all others. It is this intelligence that granted him his name among the Black Fang, "The Owl". It also seems as though Aion is somewhat prejudiced against the Nomadic people of Sacae, similarly to his 'sprite counterpart', Marquess Araphen. He refers to Uhai, the Sacaen Black Fang member previously defeated by Eliwood's group, as "useless".
Aion was assigned to defend the entrance to the Dragon's Gate on Valor, The Dread Isle, from Eliwood, Hector, and Lyn's forces. However, after the player's third turn, Kishuna, the Magic Seal, appeared, rendering Aion's magic useless. When he appears, Aion seems to recognize him, calling him "good for nothing". It is unknown if Kishuna is more well-known than previously thought, or if Aion is one of the few who knows of him.
Normal Modes and Eliwood Hard ModeEdit
*Hard Mode only
Hector Hard ModeEdit
So long as Kishuna is on the field, Aion is completely powerless. Despite this, he can prove to be an annoying opponent. With reasonable speed and luck, Aion has a solid evasion rate, a matter compounded by the fact that he is disarmed and thus completely immune to the Weapon Triangle. High accuracy weapons, as well as Support effects, can get rid of this admittedly minor problem.
In Hector's story, Kishuna will disappear on his own after a certain point. Players should avoid dawdling and deal with Aion before they find themselves caught in the range of his menacing Bolting strikes, though Aion can be easily dealt with should the player manage to directly attack him while he has Bolting equipped.
—Aion's battle quote
—Aion's death quote