The security guard was also a former soldier, so he surely wasn't weak. However, he never expected the opponent to attack suddenly with such force. He clenched his fists and tried to block, but couldn't withstand the opponent's strength, and was blasted back to the wall where his retreating steps finally halted.
His arms were faintly numb, and the security guard was shocked internally. He didn't expect the opponent to be such a skilled fighter. Although he only managed to use fifty to sixty percent of his defense in a rush, his opponent hadn't used much strength either. With just one punch, he was defeated, clearly overpowering him. Moreover, there were four of them; there was no way he could hold them off.
"Step back, or I'll call the police!" The security guard quickly got up, but before his words fell, the opponent attacked again like a big bird, not speaking, with a fierce fist wind.