Ethan is an incredibly tall and immensly muscular young man for his age with short light blond colored hair and a stoic expression at all times. He wears a tight t-shirt with dark pants and, in an effort to fit in at Kenichi's school, he was seen wearing a school uniform. When fighting, he is usually bare chested and wears a Kalaripayattu loincloth to increase his mobility.
Ethan mostly keeps a stoic expression and follows his older sister around. He demonstrates a great amount of resilience, able to get along with his sister despite being constantly ordered around and attacked by her, and expresses great concern for her well being, going as far as to punch a client who said that he wanted to "buy her" from Yami. Even though his sister rarely shows any form of care for her brother and her frequent mistreatment towards Ethan, he has shown that he loves his sister very much and is willing to do anything for her and even was saddened how he lost his fight with Kenichi, thinking she would end up dying because of his loss. Like his master, he is a very considerate person who shows little, if any, offense towards anyone, including his enemies. He doesn't seem to be irritated by others doing things that annoy him, such as when some girls were playing with him and tieing up his short hair for fun, he didn't seem to be bothered by it, suggesting he doesn't let minor things bother him. Ethan is described by Kenichi as the most honest person in Yomi: out of the rest of the Yomi transfer students, he didn't do anything bad in school, defended his classmates on the camping trip, and tries to think of peaceful solutions to solve problems, such as having Kenichi die as a martial artist once again as the best solution for both of them.
Further reflecting his contrast with his sister and his honesty, Ethan uses rather conservationist attacks while his sister uses all manners of flashy moves. When he fights, he seems to switch from a quiet giant to a raging berserker. He mostly goes all out when fighting, though he will use different stances and hit pressure points to weaken the enemy if the enemy proves resilient. Though he is on the side of the Killing Fist, he appears to be more suited for the Saving Fists. He does not attack Kenichi despite given obvious chances, takes on missions of bodyguarding, and is taking on even more missions to save his sister.
Despite his obvious Katsujiken-like sense of honesty and morality, Ethan has been trained to be an emotionless fighter who eliminates all that stand in his way, and for the sake of his sister, he is more than willing to take a life. Though he was trained to fight like an emotionless killing machine, Ethan has shown to prefer simply beating a person near-death as opposed to actually killing them, but he has shown the willingness to actually follow through if necessary, which was seen during his match with Kenichi. Overall, in spite of his willingness to kill, Ethan has shown that he would gladly prefer not to kill anyone if possible, but states to Kenichi many times that despite having no ill-feelings towards him at all that he will probably kill him if forced to.