Asterion has almost grey hair and eyebrows, and black eyes.
A yellow outfit is visible while wearing his Cloth, but during his short appearance, his casual clothing is not seen.
Asterion is able to read opponent's minds, and is thus a powerful foe to contend with, being hard to defeat.
Arriving at the beach along with Marin and Moses, they discover that Misty is killed and Seiya's body is nowhere to be found. As Marin tries to think of a way to escape, Asterion reminds her that he can read other people's thoughts, so it is no use to think of an escape. Attacking Moses, Marin is easily defeated, as Asterion keep telling Moses what she attempts to do. Deciding to use her as bait for Seiya to arrive, the tie her to a pole in the water where she will eventually drown if Seiya does not save her.
When Seiya appears, they attempt to kill him and avenge Misty, but Seiya retaliates after Moses taunts him about dying along with his sister, Marin. As Seiya kills Moses, Asterion attacks the Bronze Saint, defeating him with his "Million Ghost Attack". As he prepares to kill Seiya, Marin advance towards him, having been freed by Kiki. Attempting to read her mind, Asterion is unable as Marin has emptied her head completely.
Unleashing his "Million Ghost Attack", he is instead killed by Marin's "Eagle Toe Flash" after she sees through his attack.
Being a Silver Saint, Asterion can launch attacks between Mach 2 and Mach 5, easily surpassing the Mach 1 speed of Bronze Saints. Since he is also able to read other people's minds, Asterion may be considered one of the strongest and most clever Silver Saints.
Mind Reading: Although not a named technique, Asterion is able to read other's minds, allowing him to counterattack his enemy without them being aware.
Million Ghost Attack: Asterion soars into the air and creates dozens of illusional images of himself, and each one of them fires yellow bolts at the speed of Mach 2 against his opponents.
Asterion wears the Hound Silver Cloth, which covers his lower arms, upper chestplate, lower parts of the knees, a belt around his waist and his forehead is protected by a simple headgear.