|Height||177 cm (5'10")|
|Weight||64 kg (140 lbs)|
|Base of Operations||Aidenn|
|Favorite Technique||Zanshi Tekken|
|Likes||Order, solitude, tranquility|
Isasu is "extremely small" for his race, with long white hair, large rounded ears, turquoise eyes and spiralled black horns. He carries a turqoise and gold staff. His Chijyuujika is over his left eye. Despite his rather small figure he is extremely powerful.
His robes appear to be a mix between brown and black fur and scales. He wears a necklace of jade beads and four white pompoms that closely resemble that of a Tengu or a yamabushi. Beneath his fur and scale hagoromo, he wears a white kimono.
Isasu is cold and aloof, treating everyone with apathy and indifference. Even those closest to him never know what he is thinking. However, he is both ruthless and just, and treats even enemies with diplomacy and fairness, as seen when Ryouta insults Madoka.
It is revealed, to the surprise of many other characters, that Isasu hates blood. His distaste for blood seems to fit in with other aspects of his personality, such as his peculiarities about keeping things clean. He is unfazed by the blood itself, which causes hunger or phobia in several other characters, and life-threatening wounds hardly faze him.
Around 800 years before the current timeline, Isasu was a young Seraph. He had chin-length hair and barely any horns, and was constantly teased by other young Seraphs for his huge ears and nonexistent horns.
- Breathe fire.
- When he is angry or ratcheting up his spiritual powers, he appears to be engulfed in white flames. Also, when he is ratcheting up his ki, the black lines around his face, neck, and eyes become more defined.
- His hagoromo is a thick, impenetrable hide of scales and fur. It is resistant to fire and most physical attacks.
- Isasu is said to have very good hearing. He alway seems to know what others are talking about, even from a distance. Ryouta commonly attributes this to his ears, "which are large enough to take an eye out."
- He appears to be slightly OCD, or at least extremely neat. He is careful not to disrupt anything around him, down to blades of grass, which Ryouta and Ryuuhei are quick to note--and mention.
- "You made me walk on the grass."