This is probably the closest reference imo to Luffy vs Kaido. Typhon can sometimes be referred as a
dragon. Typhon's appeance varies from version to version, from
a giant humanoid to a strait up Kaiju Monster or a mix of the 2 much like Kaido with his Oni, Dragon, Hybrid forms.I forgot to mention, Kaido was also called a wisdom king/deity & Typhon is a Titan, still a god. Typhon is the father of all fantastical beast in greek myth & the monster of Gaia while Kaido is the king of beast & the world's strongest creature. Both can breath fire, cause winds & storms. The Nika in Luffy's Devil Fruit might be inspired Nike, the Greek Goddess of Victory(supposly responsible for Zeus success too)
& also Zeus sometimes being refered as a sungod. After Luffy fell from Onigashima, he needed help from Law crew to go regain his strength back much like Zeus needing Hermes & Pan to get his tendrils back after his 1st round with Typhon. Both can grab lightning bolts, throw them like spears, are great leaders despite being young compared to most, have good shapeshifting, possesses the same hair color(Zeus hair can be either black or white in art & Luffy changed his hair color from black normally to white in Gear 5th), fought giants & change the weather. There's also theme of the newer generations taking over older one in both OP & Greek Myth.