Looking at the old man who was looking at him while he lay on the ground, Derek was furious. He jumped to his feet and pointed at the old man as he questioned, "What the f*ck was that? Are you trying to rebel?"
Derek was furious. He was a person who was currently at the 10th Star of the ordinary human level. So, he was still able to remember what had happened. Although he was not given a chance of reacting before he was knocked unconscious, he was still able to remember vividly what had happened.
At that time, he was planning to deal with Alicia first. And after that, he was going to deal with Jack, before getting his hands on Celine. But, everything went wrong with the intervention of the old man.
He prevented him from doing what he wanted, something that infuriated him. Moreover, he was knocked unconscious, something that had never happened before.