He is a genetically augmented super soldier that has been around for ten thousand years. He is also powered by a god, which makes him even stronger. He picked up a mech, he has invaded thousands of worlds. Killed multiple billions. He picked up a mech suit that is about that was just huge. He is faster than normal space marines which are bullet timers and are better than spartan 2s. Genetically better in everyway. His axe devours souls. He moves at hyper sonic speeds, can react to light speed weapons and more. Kharn would kill Spartans like it was just another day in the office.