Seth had thought up a lot of solutions for possible scenarios, but that his spinal cord would be injured hadn't really crossed his mind, and despite Zuroc being the enemy he had to applaud the man for his smart thinking.
Were one of his hands to have been severed, Seth figured he could ride through the pain and use his other hand to attack, and as for the chance of both his hand being cut, well that was almost impossible.
As far as Seth knew, the ritual needed someone alive, and unless Zuroc was a dummy which he had proved he wasn't, then severing both of Seth's arms would only end up killing him.
With the amount of blood, Seth had lost from his injuries, cutting both his arms should only cause a near-instantaneous death, and so Seth was quite sure Zuroc wouldn't take that option.
Creation is hard, cheer me up!
Creation is hard, cheer me up!