Half of the battle was pain and it just so happened that Blackthorne thrived upon it. Each claw that scratched through his fur and left a mark focused him, strengthened him, and he continued his assault in a vicious fury. They were a roiling mess of paws, claws, and snarls as they tear at each other. Zharko's ear had been torn and shredded with as much fervor as Blackthorne could inflict and in return his face now sported bloody cuts, his right eye smarted from being smacked, and both his chest and legs had bites and scratches.
It took considerable effort on Zharko's part to maneuver himself out from beneath the black and silver fiend but eventually he manages and pulls away with Thorne staring at him with glittering eyes and parted jaws, his blood pounding within him with the desire to assault him some more. Except that Zharko lowers himself a bit, tucks his tail, and growls. It was a clear admission of defeat but also a challenge that he would fight back once more if need be.
So it sealed the deal and Thorne sat down abruptly with a prideful grin, eyes focused solely upon his newfound friend.