Actually, the king was in such a fit of rage that he could only attack everything in his sight.
However, his self-control won. He didn't want Emma to hate him even more if she saw him flying in a fit of rage. She was still emotionally vulnerable after giving birth. Perhaps, she needed time to think and forgive him.
He could only ball his fist and punch a wall.
"ARGH! What's so good about Taeshi?! This place is—"
"How dare you enter my sister's quarters!" Prince Aran stormed into the room with a sword, accompanied by his people, and pointed it at Therius. "You have manipulated my men for too long. You will leave now or we will not hesitate to kill you. Even if I have to die, I will not let you hurt my sister again!!"