Get into the Cage by Yourself, I Don't Want to Talk Nonsense

My name is Memorial. This is the third year since I traveled back in time. This is a world where you can be king based on your strength. Coincidentally, I am the boss here. Before I traveled back in time, I was a martial arts prodigy. I have won all the awards in national martial arts competitions. Who knew that I would be here after sleeping at home and opening my eyes. I was helpless. I had to fight to survive. I accidentally became the boss. Finally, the system prompted me to complete the last task and then I could go back...