Cassiel.

Cassiel sees that the girl was napping on his favorite bench and notices it with bewilderment. A twig snaps under his boot; Audrey starts, looks around, jumps up from the bench, and grabs a stick. Cassiel quietly approaches the girl and places his hand on her shoulder. Startled, Audrey lets out a squeak, jumps, and whacks him with the stick. Cassiel doesn't even try to dodge the blow, only looking with disgust at his stained shirt.

Cassiel deals with security issues at the Astrea detective agency.

He is taciturn and sullen when he hears that Audrey is joining the team as the agency's psychological evaluator. When they talk in the garden, he tells her that he doesn't believe in psychology. Audrey notices a scar on his cheek and a streak of gray in his hair, making Cassiel seem to bear the painful marks of his past. Cassiel believes that a man is made not by his words, but by his actions.
Loves animals much more than people.
He doesn't care whether people like him or not.
As a child, Cassiel crashed into a floating island during a flight, his wing did not have time to regenerate and it fell into the water. Almost immediately, sirens attacked him, dragging him to the bottom. After a night in the water, fighting off sirens, Cassiel was saved by his sister, who found him through the thickness of the water.
According to the scriptwriter, if Cassiel had studied at Hogwarts, he would have been sorted into Gryffindor.
The writer is inclined to believe that Cassiel's MBTI personality type is ISFJ.