He has good technique and an understanding of angles, and the ability to keep his opponent stumbling/off balance continously, a large part of it all is that he not only has heavy hands but heft in all his limbs. He can graze his opponent and it might just feel like a strike from another elite mmartist without the added power from having heavy hands/limbs.
Also the most efficient & powerful strikes are thrown with weight going downwards, so in mount you'd have to be in uncharted territory or Chael Sonnen if you aren't gonna knock the dude out otherwise your opponent would need an otherworldly chin.