The weather outside was rather stable but changed here to a huge rainfall that poured down, making the feeling of fear that the Demon King experienced even stronger.
After a quick stumble that he experienced, Demon King regained his composure and was ready to fight to the death.
After looking around, he said, "Ever since coming to this world, not a single being was able to harm me. But you not only did damage to me. You made me feel fear. As a reward for letting me taste new emotions, I will kill you the most painful way possible to let you feel some fear as well."