Nak Soo Mahakarn (The Ultimate Hero)

Ritravee, a combatant agent who retires from this killing career and returns to his hometown to open a martial arts self-defense school. But once there is a high stake secret mission, he accepts the job because he is a patriot. However, the mission goes awry and Ritravee is harmed. The biochemical laboratory explodes and the supernatural drug seeps into his open wound, causing Ritravee to obtain superhuman powers. The Ghost Assassin is born within Ritravee. Will he be able to overcome the obstacles?