Toughest? Definitely. Though noticeably not the strongest. Considering the only injury Fury has sustained are a few broken ribs and now a slightly crushed ankle.

Put simply, surviving is all he can really do at this point. He cant throw punches anymore because his leading hand is broken and he doesn't have enough stamina to run anymore. His leather hard skin, rock hard bones, and metal coated muscles are keeping his organs protected.

I figured you would have picked up on him no longer trading with Fury and simply taking the hits. Kanitah stopped counterattacking a few posts back because he has already, in all honesty, lost. His last offensive attempt, aside from the poor grapple, was a dirt ball that was doomed to fail from the start. 

Other than that, his last truly threatening attack was the full speed ram. I kinda figured you would have seen that after 9 posts of Kanitah just taking the hits.