I haven't been a big fan of the psycho-MC, but I think this chapter is hinting that there might be more going on than what we're seeing. A lot of what he did was very calculated. He starts off the fight by trying to intimidate his opponent and then favors wild and unpredictable tactics to keep a, probably, better and, definitely, juiced opponent off balance and unable to apply their full strength against him. If he had tackled it in a more calm and rational manner, then his opponent would have had the footing to reasonably respond and that would have been the end of our hero.
Now we see him going for "dirty" moves, but he only started that after finding out that standard trauma wouldn't be enough to put his opponent down until it reached lethal levels. Once he had that realization it was like a switched flipped and he went strait in to psychological attacks and maiming attacks. Again, this keeps his opponent off balance and does damage they can't ignore. A more measured response would probably result in him getting his face creamed.
Through all of that, he looks psychotic,but he never does more damage than he intends and he keeps stopping his attacks to offer his opponent a way out or to give the ref a chance to end the fight. That shows he has way more control over himself than he's letting on and that he's not really in this to cause pain and kill people. Now my question is when will his facade crack.