When he saw his daughter and dagger in the hands of the enemy, King Edge only had one thought in mind, he wanted Lu Sin dead! Who cares if it might lead to future wars! He simply couldn't let the other get away with this tyrannical behavior.
He looked at the armored man beside him expectantly. His eyes conveyed the killing intent he felt. The Regent was stunned by the look, he could only say helplessly, "Your Majesty, I can't kill him."
"And why not?"
"Well, because..." Snow looked over at the Demon Venerable almost as if to say 'his father is right there!'. Besides, not to talk of killing, he doubted he'd be able to subdue Lu Sin. The Demon realm practiced martial arts that were against the law of heaven. They did all sorts of unruly things, it allowed them to become stronger but only at some certain costs.