Shanks is one of the most important characters in the world of One Piece.
He’s also one of the very first characters that Oda introduced in his story, courtesy of the Romance Dawn arc. From the very beginning of the story, it was quite clear that Shanks would be a crucial character moving forward. He inspired Luffy to become a pirate and put him on the path of finding the One Piece.
How Shanks Lost His Arm

Shanks ended up losing his arm at the very beginning of One Piece. This event actually took place 10 years before Luffy set out on his journey and fans only got to see it through a flashback. Luffy spent the vast majority of his childhood in Foosha Village and there, he met a pirate named Shanks who had been camping in the East Blue for around a year. Luffy became great friends with Shanks and his crew and immediately took a very strong liking to him. Eventually, he wanted to join his crew and to that end, Luffy often wanted to prove his bravery to Shanks, given that the red-haired pirate was a person he respected quite a lot. However, when, one day, Higuma, a mountain bandit came down and disrespected Shanks, Luffy was absolutely infuriated at his inability to do anything about it.
Oda’s Original Plan For Shanks

Shanks giving up an arm for Luffy made the Romance Dawn arc of One Piece an iconic arc. It is the most memorable scene from this arc and one that has reverberated through the history of the series. To this day, fans recognize that scene as the moment where it all started. It is also very apparent that Luffy’s respect for Shanks, which was already great, elevated even further after this. The fact that Shanks was willing to give up his arm for Luffy and potentially even his life just goes to show that he was, indeed, like a guardian to him. Furthermore, it also taught Luffy about the meaning of sacrifice. When Sanji was willing to give up his life for the sake of Zeff, it was Luffy who stopped him from doing that, telling him that Zeff did not sacrifice his leg so Sanji could give away his life. This forced Luffy to mature at a very early age in certain aspects and has shaped his character to this day.
How Shanks’ Character Was Affected

Meanwhile, Luffy will end up meeting Shanks once again, and when that happens, fans will get to see an incredible reunion between these two characters. Perhaps, more value would be attached to Shanks’ arm that he gave up for Luffy when these two come face to face. For now, fans can only sit back and wait for this incredible reunion to happen. One Piece is now in its final saga and that only means this reunion is now very close.