Ace’s Promises to Luffy and it’s relevance to Wano
During Luffy and Ace’s flashback, we learn that Ace once promised Luffy that he would never die, a promise that he obviously failed to keep. However, this promise is much more layered when you take into account the dynamic the two brothers had.
Luffy has been chasing Ace his entire life. When they were younger, Ace was always the superior fighter, and when Luffy first set out to be a pirate, he did so with every intention of catching up to Ace despite his older brother’s three year head start. When the two meet in Alabasta, it’s established that Ace is still stronger than Luffy and when Ace departs, he promises Luffy that the two will meet again at the top of the pirate world. Luffy accepts because one of his goals since he was a child is to one day be stronger than Ace, and the two brothers depart with this promise at heart.
However, Ace dies at Marineford; ironically meeting his brother at the top of the pirate world, but before Luffy is strong enough to uphold his end of the promise. When Ace dies in Luffy’s arms, he’s doing much more than breaking a promise, he’s robbing Luffy of the satisfaction of one day being able to surpass his brother. This is, in part, what makes Ace’s death so tragic, but it deepens the connection between Luffy and O-Tama because Ace’s death results in the same thing for both characters: a broken promise.
What I find amazing is that Oda chose to bring Ace back into the story in Wano, because Wano is the point in Luffy’s journey where he’s finally set to surpass Ace in terms of strength. Right now, with Luffy being commander level, one can argue that he’d be an even match for Ace, but after Kaido goes down, Luffy will have risen to a level Ace has never achieved. Ace was never able to beat Whitebeard, but Luffy will have beaten Kaido. Finally, Luffy will be stronger than his older brother, and his brother won’t be around to see it.
This is why O-Tama is so important. In an arc that has such a strong thematic focus on honoring the dead; with a festival specifically designed to remember those who have passed; at the point in the story where Luffy is finally poised to surpass his older brother, something he’s been wanting to do since his childhood; with Ace dead, O-Tama is the only character who’ll be able to relate to Luffy on this specific level because she too had a promise broken by Ace’s death. Together, the pair will honor Ace during the arc’s conclusion, and Luffy will take Ace’s place as her role model. This is also why Oda had Luffy use Red Hawk specifically to rescue O-Tama, in order to establish this connection.
Thematically, this is also the perfect time for Luffy to visit Ace’s grave, which is likely the message Marco wanted Nekomamushi to relate to Luffy. Now that Luffy has finally caught up to Ace, it’s time for the brother to meet one final time, at the top of the pirate world, just like they promised.
*Theory by Therrester
