Sensei Seth is pretty cool.
He's a 4th degree black belt in Karate who has made a career out of trying out as many different martial arts and combat sports as he can and filming the results, basically.
He's actually now a 2X US amateur national Sumo champion, and Sumo was just one of the many random martial arts he tried out on a whim for content on his cannel.
He also has become a green belt in Judo in very short order, and he filmed his first tournament and his belt test.
He's done videos on boxing, taekwondo, muay thai, catch wrestling, savate, sanda, frontier wrestling, bokh (mongolian wrestling), backhold, brazilian jiu-jitsu, sambo, capoeira, pro wrestling, stunt choreography, silat, MMA, aikido, systema, keysi, and others.
He's not afraid to show himself getting his butt kicked by his instructors or the more experienced students. He's also very collaborative and brings in many people from other martial arts Youtube channels. He has an ongoing series with Icy Mike from hard2hurt where they literally test self defense weapons on each other (nothing funnier than guys spraying each other with pepper spray just to see how much it hurts, for science).