Kushiel is one of the Powers, those who have power over evil forces and tasked with keeping them from doing harm.
Conversely, as an Angel of Punishment, he can bring that evil upon humans in divine retribution.
Kushiel isn't Fallen, but he does work with hell, so there's an element of him that isn't completely divine. He walks the line of divine and infernal in punishing others.
He dresses what might be termed as business casual on earth, an easy sort of dress involving button up shirts and slacks or dark jeans.
Carniela and Celael were created at the same time as other angels, but their closeness after creation is what makes them more twins than siblings. They are Virtues, tasked with governing nature.
Carniela is Angel of Fauna, particularly the creatures of the woods.
Celael is Angel of Flora, particularly wildflowers, and he does have a habit of weaving flowers together.
The twins tend to be barefoot or in sandals when on earth, sticking to small towns or nature entirely. Major cities are suffocating for them both.