In reality, Warrior MMA is purely fictional. It's designed to entertain through imaginative scenarios and characters rather than being based on actual happenings.
One great story is about Anderson Silva. He had a remarkable reign as UFC middleweight champion. His unorthodox striking style and ability to finish fights in spectacular ways made him a legend. For example, his front kick knockout of Vitor Belfort was iconic.
Yes, Caiyun Kingdom Monogatari had ended. There was no official announcement for the third season, but according to the author Aoyama Gangchang's latest statement, he had clearly stated that he would not continue to write the third season of Caiyun Kingdom Monogatari. Therefore, we are not sure if there will be a third season.
The ending of the first season of Caiyun Kingdom Monogatari was that Wedding Candy sacrificed herself together with Hei Yu Kaito to save the future of Caiyun Kingdom. The ending wasn't sweet or not, but it was very sad.
The plot could revolve around Percy trying to keep his identity as a demigod a secret while competing in MMA. He would have to constantly balance his normal life and his demigod powers. Maybe there's a tournament where the final opponent is someone who knows his secret and is out to expose him or defeat him in a more sinister way. And along the way, he could make some new friends or allies within the MMA world who help him keep his secret.