Sebastian Debeste is a rookie prosecutor. He takes over some of Miles Edgeworth's cases. Which was headed by his father Blaise. Although he graduated at the top of his class, he soon become to the point of being ridiculed. But after the talk with Edgeworth, he started to reform his ways of thinking.

Sebastian is 17 years old, and he is 5'8. He was born in 2002. Sebastian Debeste was raised by his prosecutor father Blaise Debeste, who would often verbally abuse him.