Note: Gruesome scene ahead.
The third point of view:
Niklaus was grateful for the fact that he had not brought Reina to this place else he would not have tortured Miguel to his heart's content- it was a known fact women were not a fan of violence.
Niklaus's heart was hardened because the only thing that he could think about was what would have happened if Reina and his kids had died in the bastard's hands. What would he have done? Because he was sure as hell that his life would never remain the same.
The blood-curdling scream from Miguel didn't move both men - Niklaus and Sakuzi - watching the scene with an expressionless face. Instead, they were busy analyzing the location that would cause him more pain.