@saiyan_earthling: No I watched this anime (Don't remember the title, It was demon king something?) But It focused on Raoh and how he built his empire. At the end of the season he fought this guy with a reverse nerve system or something.
@GrandSymbiote94: That's Ten no Haoh. It's a spin off to Fist of the North Star. It did focus on Raoh, but Ken is the real main character of the series. Raoh fought Souther, the man with the reverse nerve system as you mentioned, to a draw.