The Interrogation

From his experience, the more delicious and nutritious the blood is, the more powerful the owner was when he or she was alive.

Which was the exact reason was so confused he wasn't able to notice his cracked claws at first.

He was only able to feel the pain after the adrenaline had faded by a bit.

It was the claw he had used to stab the kid's body. Currently, amongst the five claws, three had being twisted into odd angles, it was only his thumb finger and his index finger that was okay.

Which means the kids bones were just too strong and he wouldn't have being able to penetrate through his ribs with his own strength of he hadn't used the opponent's strength against himself.

Which also means the foe was a very strong one and like he had said after David inflicted a fleshy wound on his, he had only been toying with David previously.