In 'luffy vs kaido fanfiction', Luffy's growth and new abilities are often explored. He might develop new forms of his Gear powers to face Kaido. Kaido, being extremely powerful, forces Luffy to push his limits. Fanfictions may also focus on the intense battle scenes, with detailed descriptions of their attacks and counter - attacks.
There's not enough information to know exactly who Rayleigh is. It could be a common name for a person in this context, maybe a local storyteller or someone known within a particular community.
Another plot twist might be that Luffy actually loses the first round of the fight but then finds an inner strength or a new power - up from an unexpected source, like a memory of Roger or a new Devil Fruit ability that he unlocks in a moment of desperation.
Yes, there might be. The world of fanfiction is vast, and with the popularity of both Naruto and Kaido from different fictional universes, it's not unlikely that someone has created a crossover fanfiction where Naruto has some sort of connection to Kaido. You can search on popular fanfiction websites to find out.
Well, 'rayleigh tells story' might refer to a situation where Rayleigh, who could be a storyteller, a character in a certain setting, or just an individual named Rayleigh, is in the act of narrating a story. Maybe it's a bedtime story for kids, or a spooky story around a campfire. Without more details, it's hard to say exactly.