The Fishman Second Generation referred to Xiao Yan in "Battle Through the Heavens" as the genius of the younger generation of the Xiao clan, who trained in fire affinity Dou Qi.
Other than that, there were also some novels related to Xiao Yan such as 'The Peak of Martial Refinement',' Douluo Continent','Peerless Martial God',' Covering the Sky','The Great Dominator', etc. These novels, along with Battle Through the Heavens, were very popular and well-known, becoming classics in online novels.
Sure did. Luffy overcame many challenges and ultimately emerged victorious against Kaido. It was a long and hard-fought struggle that showcased Luffy's growth and determination.
There's a fanfiction where Kaido is portrayed as a mentor. In this story, he imparts his knowledge and power to a young protégé. It's an interesting take as it shows a different side of Kaido. Then there's the fanfiction that focuses on Kaido's battles from the perspective of his enemies. This gives a fresh look at his combat abilities. Also, some fanfictions explore Kaido's relationships with other characters in the One Piece universe in more depth.