Most of the characters call him "Captain Strydum" (キャプテン・ストライダム, Kyaputen Sutoraidamu).
A Captain and later general in the US Army and Yujiro Hanma's companion and comrade-at-arms. He developed an admiration for Yujiro, and now he travels, fighting with him on the battlefields across the world. He somewhat understands Yujiro's mentality and mentions that he is the only person to bring the United States to its knees. He is also a friend and mentor of Baki's, who keeps him up to date about Yujiro's whereabouts.
Strydum is a very experienced soilder and fighter, as shown in the manga. While fighting against several well trained fighter he had hand picked. The first one he beat with a groin kick when Mark tryed a high kick. He then pocked the eyes of a judo practicioner, threw a boxer on the ground, knocked out a wrester with a punch, tied a chinese martial arts fighter up in his gi and belt, etc. He did all this as a lesson on private martial arts verse battlefield fighting. And, he also did it all with one move each.
Strydum is good in using weapons and explosives. He once put on himself an armor that had explosive power in his knuckles and his boots. The armor also covered his body weakness. He wanted to fight Yujiro in this form, but despite all that, he was no match for him.