I’m aware that Shanks losing his arm was influenced by editorial input, but I think there’s a compelling theory that could fit well within the story. This theory has two parts:
1. The Loss of Shanks’ Arm
We never actually saw how Shanks lost his arm. Given that he stole the Devil Fruit from the World Government, it’s possible that agents or an operative followed him to the village where he lost his arm. One possibility is that, similar to how an agent threw a slice kick during Luffy’s fight with Kaito, Shanks might have been ambushed by an agent. Instead of being hit, Shanks could have used Conqueror’s Haki to neutralize the threat. The sea beast involved may not have been a direct threat to Shanks but could have been part of a broader plan by the World Government. It’s worth considering that an ancient weapon might control sea beasts, and the attack could have been an attempt by the World Government to eliminate Nika (the Nika Fruit) early on.
2. The World Government and Luffy
I’ve always wondered why the World Government didn’t actively pursue Luffy, despite knowing about his unique abilities, which are connected to the Nika Fruit. One possible explanation is Shanks’ role in protecting Luffy. Shanks’ presence seems to have been strategically placed throughout the series. He met with Mihawk around the time Mihawk fought Zoro, and he interacted with Ace when Ace was near Luffy. Recently, Shanks has been seen sending giants to assist Luffy and guarding him during the Wano arc.
The theory suggests that Shanks has been subtly protecting Luffy from the World Government. His arm loss might have been due to an attack involving an ancient weapon, a World Government agent, or a sea beast controlled by the World Government. Shanks’ presence and his actions could have deterred the World Government from pursuing Luffy aggressively.
It’s possible that Roger informed Shanks about Luffy’s importance. Buggy’s recent thoughts about Shanks and his potential hint that Roger might have told Shanks that while neither he nor Roger would change the world directly, Shanks was to protect and guide a future figure who would. Roger may have mentioned that Luffy, marked with a “D,” would be the one to change the world.
In summary, this theory posits that Shanks lost his arm due to a World Government attack and has been shielding Luffy throughout the series. His role has been to nurture and protect Luffy, helping him become the one who will fulfill the prophecy and reshape the world.
