He can't see. He can't see anything, he can't slither out of her grasp. He hisses and writhes about helplessly, trying to get away, do anything, get anywhere---

He doesn't even see the blade come down at him, he just feels it as she stabs him, down below his first rib cage. The cry he makes sounds like a man's, even as the serpent, and he tries to transform back---giving himself clothes as he does---to give himself more body if she stabs him again. He could handle one stab as a man, but not any more as a snake.