Samuel Brent Oscar Riegel (born October 9, 1976), also known as Sam Regal, or Jack Lingo, is an American voice actor, writer and director who appears in cartoons, anime and video game series. He voiced Donatello in the 2003 Teenage Mutant Ninja Turtles series, Phoenix Wright in the Ace Attorney video game series, Shiro Emiya in the Fate/stay night series, Taniguchi in The Melancholy of Haruhi Suzumiya and Mephisto Pheles in the Blue Exorcist series. He is also a cast member of Critical Role.