According to the information provided, the strongest person should be the main character, Xiao Yan. Xiao Yan was the first male lead in the novel 'Battle Through the Heavens.' He was also the main character in the previous novel,'Battle Through the Heavens.' In this book, Xiao Yan entered the Great Thousand World in the 'Great Ruler' and created the Endless Fire Region, becoming the strongest Xiao Yan. Their levels were Supreme, Earthly Sovereign, Heavenly Sovereign, Ruler, and Heavenly Emperor. Hence, it could be said that Xiao Yan was the most powerful among the people who had appeared. I hope you like this fairy's recommendation. Muah ~😗