Lord Osanos is one of Mare and Cal's executioners in the Bowl of Bones. When Stralian Haven, a fellow executioner, is burned by Cal, Osanos lazily uses his ability to put the fire out. He uses his ability to put out Cal's wall of fire, flash-boiling it into thick clouds of steam that settle through the arena like a fog. He battles Cal. Steam screams from the clash of water and fire, but water is winning. Osanos is the true executioner. Osanos traps Cal in a swirling orb of water. Cal tries to fight back, boiling the water, but a burner is weaker than a nymph.
Upon Rane Arven's death, Mare's lightning is returned to her. She kills Ryker Rhambos, another executioner, and then comes after Osanos. She electrocutes him, which dissolves the orb of water around Cal. Osanos gets back on his feet, and continues attacking Cal, with Ptolemus Samos' support. Mare grabs Osanos' wrist, shocking him through his skin. He turns his ability on Mare, knocking her back into the sand. He pounds her with water, keeping her from breathing. When she opens her mouth, water pours in. She lets a spark shock through the water and up into Osanos. He jumps back long enough for Mare to escape. He grabs her around the neck, holding her under a swirling foot of water. But he is touching her skin directly, and she lets her lightning loose, shocking through flesh and water. He screams and the water drains away, leaving his dead body.
He is a typical cruel Silver. He seems to enjoy being one of Cal and Mare's executioners.
He has startling blue eyes.
- His first name is unknown.