Novel Kharn is a totally different beast. He has the durability to stand up to 100+ tonners. He stood back and just let Angron beat him up. Angron was seen lifting 2 thousand tons in the battle of Terra and Angron couldn't even get Kharn to stay on the floor and he just stood there taking every blow without retaliation and that was without his demon armor. That was just standard pre-chaos Kharn. Current Kharn makes him look like a puppy. Due to his healing factor I doubt anyone on there other team can take Kharn 1v1. 100+ tonners can't beat him down.
While most of this is true. Kharn was not unhurt by Angrons attacks he was bleeding badly and had he wanted Angron could have most likely killed him but when he saw how determined Kharn was made him his second in command out of respect. Another thing to take into account is that while Kharn's durability to blunt trauma is good penetrative is another matter. He let Angron lay down 100 ton+ punches on him and yet he was knocked unconscious when that tank tore out his chest. Kharn is still vulnerable to getting his head chopped off or cut in two. The bleach team is also faster than him which may allow them to get in the necessary hit. It's the same principle as Hulk. If you punch him that won't do a thing. you slice his head off however its a different ball-game.
Hasn't Hulk survived being burnt down to the flesh and many other rather nasty things? If Kharn has a healing factor now on top of what he already accomplished, I can't see the Bleach team getting in that many powerful hits, especially not with three other dangerous opponents fighting alongside him.