Whit was a mercenary from the United Kingdom who ended up in feudal Japan, initially under the employ of Walker, before he attempted a mutiny. He is first found in Norinaga's prison, and meets April when she is sent there as well. It is heavily implied that Whit is an ancestor of Casey Jones, due to his striking resemblance (sharing the same actor in the movie), and his overall demeanor, including his romantic interest in April.
Whit first encounters the Turtles when they come to bail April out of the dungeon prison. He escapes at the same time, heading out before them. He joins April and the Turtles at Mitsu's rebel camp, but he later reappears working for Walker again, kidnapping Mitsu and taking the Time Scepter. However, due to mistreatment from Walker and his stooge Niles, Whit turns on them in the end, and launches a catapult at Walker, knocking him from a rooftop into a long drop into the ocean, killing him and saving the day.