Shanks is one of the most important characters in One Piece and is known as a key figure as the story enters the Final Saga. He is also regarded as the Child of Destiny and the one who set Luffy on the path to becoming a pirate.
Shanks is one of the Four Emperors, having earned this position six years ago. While he is famous as a master of Haki, there is another ability Oda has hinted at: a Devil Fruit power. Although surprising, evidence in the manga strongly supports the idea that Shanks possesses a Devil Fruit.
Shanks’ Sword Might Hold His Devil Fruit Power

Shanks mainly relies on his powerful Haki skills in battle. He developed his Haki abilities very early on. Oda confirmed that before the age of 15, Shanks could already use advanced Conqueror’s Haki.
Although Shanks is considered a Haki prodigy, it’s important to note he also has the potential to be a Devil Fruit user. He certainly couldn’t have eaten a Devil Fruit himself (since he saved Luffy from drowning), but he doesn’t necessarily have to consume one personally to wield such power.
The real secret behind Shanks’ Devil Fruit power lies in his sword, which is almost certainly a Supreme Grade blade.
The Gryphon Sword Changed After Romance Dawn

When One Piece began, Shanks was seen carrying a sword with a very unique hilt. He used this sword for quite some time. However, after the timeskip at the end of chapter 1, Shanks gained more influence and power. At this point, he wielded a new sword. Interestingly, Oda named Shanks’ sword Gryphon.
For those unfamiliar, a Gryphon (or Griffin) is a mythical creature with the body of a lion and the head, tail, and wings of an eagle. Curiously, Shanks’ spirit animal is also a lion, which Oda says fits perfectly with the Gryphon theme.
Evidence from Shanks’ Brother Shamrock

In the Elbaf arc of One Piece, fans met Figarland Shamrock, Shanks’ twin brother. Upon his introduction, Shamrock showcased the power of his sword named Cerberus. Fans quickly noticed Oda drawing a parallel between Shanks and Shamrock.
Shamrock’s sword is named after a mythical creature (Cerberus, the guardian of the underworld), and Shamrock demonstrated the power of a real Cerberus emerging from his blade.
Shanks’ sword closely resembles Shamrock’s visually and is also named after a mythical creature (Gryphon). It’s easy to infer that Shanks uses the power of the Gryphon.
Oda himself supports this idea by describing Shanks’ fighting style in vague terms. This ambiguous wording suggests Oda is deliberately hiding a major secret.
The question: “What is the name of Red-Haired Shanks’ sword?”
The answer: “Clearly, it’s called Gryphon. We’ve known Shanks since the first chapter, but how does he actually fight?”
This also explains how Shanks moves so quickly from place to place. For example, during the Summit War, Shanks traveled from the New World to Marineford almost instantly. If his sword can transform into a Gryphon (with wings), that would explain how his ship arrives so fast.