Teisel has a very strong and imposing figure, always clad in a suit of green armor, but he is actually more the type to rely on intellect than strength, and he serves as the primary strategist for all the Bonne Family plans. So that no plan ever fails twice, he makes it a habit to have reviewing meetings with the rest of his team after a failure. He also pilots many of the battle machines his sister Tron creates, including the Marlwolf, Balcon Gerät, Theodore Bruno and Blitzkrieg. Besides Tron, he has a younger brother Bon.