This Old Man Only Wants Immortality, Don't Make Me Draw My Blade

[Martial Saint] [Hero Is Sixty] [Multiple Heroines] [Invincible Power Fantasy] Xu Kun. A transmigrator. He only obtained a martial arts System at sixty, when his life force was nearly spent. Each time he practiced a fist technique, his progress multiplied a thousandfold. Breaking through realms was as easy as eating or drinking. Xu Kun said, “I just want to live forever.” But there's always someone standing in his way. What should he do?