This would be so much simpler if he intended to kill the child. Nhodd can hardly keep a grip on the squirming thing, and he has to abandon his efforts to snatch the flailing knife-hand out of the air in favor of grabbing at the shoulder and sliding a much firmer grip down the arm again to end at the wrist. It is not ideal; the stabbing motions necessitate a constant dodging away and he grunts as the human scores glancing blows along his torso that leave his shirt torn and body bleeding.

No matter. It will be repaired, or it will not matter when he de-manifests. It only matters that he hold the child still and force him to drop the knife.