I actually have some different thoughts about the 'Nine Shadows', though I do think Yamato could team up with the others.
Toki's Prophecy of Nine Shadows and the 'Dream of Wano'
Amatsuki Toki foretold Nine Shadows cast by the moon liberating Wano from the clutches of Kaido and Orochi on a night 20 years beyond the day of Oden’s executio. It was widely believed this prophecy signaled the return of Oden’s nine retainers, the Akazaya Samurai or Nine Red Scabbards. Indeed, we saw Oden’s retainers battle Kaido on the roof of Onigashima between chapter 987 and 1000. Kaido however emerged victorious and the scabbards were transported by Trafalgar Law to safety in the castle below.
Preently, Luffy, Zoro, Law, Kid, and Killer have stepped in and are now battling Kaido and Big Mom in the stead of Oden’s retainers. Yet, as the battle continues, it is becoming increasingly apparent that, despite holding their own for the time being, unless the alliance gets some major strength boost, this fight will not end favorably. This is of course where the idea of Gear 5 enters the picture – a major powerup / new form for Luffy would seem to be the perfect solution to this problem, right? I’m not so sure, and I’ll explain why there may be an answer which fits better both narratively and thematically – Nightmare Luffy.
Toki’s prophecy reads “You are the moon, unaware of the Dawn. May your purpose be fulfilled and cast Nine Shadows on the night woven of 20 Years and you shall know the brilliance of the New Dawn.” The New Dawn here likely has double meaning – it alludes to the liberation of Wano from Kaido and Orochi as well as the fulfillment of the 800 year old prophecy and the liberation of the entire One Piece world which will follow the discovery of One Piece and the True History of the Void Century.
During the Thriller Bark arc, Luffy and other members of their crew have their shadows stolen and need to defeat Moria before dawn. The climax of the battle between Luffy and Moria takes place just as the sun peeks over the horizon. So this seems to directly foreshadow the battle between Luffy and Kaido on Wano. The battle against Kaido is taking place on the night of the Fire Festival under the light of the full moon. I can easily imagine the battle lasting until Dawn – with a shadow powered Nightmare Luffy taking down Kaido.
I particularly like the idea that the Akazaya Samurai shadows are borrowed to power up Nightmare, or maybe more accurately ‘Dream’ Luffy. Toki sent them forward through time and they have persisted in carrying on Oden’s Will for a reason. Those celebrating the Fire Festival in the Flower capitol entertain the dream that Oden’s retainers believed to have died long ago are currently battling Kaido and Orochi on Onigashima. They were pretty soundly defeated, but infusing their shadows into Luffy would be a great way for them to still have a hand in Kaido’s ultimate defeat.
Samurai Ryuma, whose zombie Zoro fought on Thriller Bark, is famous for slaying a dragon. I mentioned the fact that Nightmare Luffy wielded a Katana – and so perhaps Luffy, carrying Oden’s will and the shadows of the Akazay Samurai will bring this ‘dream’ to life, serving as a mortal vessel for these ghosts of Wano’s past, will use a Katana to defeat Kaido, echoing the heroes of Wano’s past – Ryuma and Oden.
Luffy Needs a ‘Power-Up’
There are, in my mind a few problems with Luffy deploying Gear 5.
Luffy appears to be going all out against Kaido. There’s no reason to assume he’s holding anything back, so if there were a more powerful form available to him, I struggle to think of a reason he wouldn’t lead with that when battling against two of the Four Emperors.
Luffy has often synthesized knowledge from past opponents to develop new techniques or forms. It’s hard to imagine exactly what new techniques or knowledge Luffy could put to use in a new Gear at this point in time. Luffy has already been using the advanced Ryou he learned from Hyogoro in Udon prison and future sight observation haki he learned from his battle with Katakuri.
The natural next step for Luffy seems to be Awakening of his Devil Fruit, but I get the impression we will need to be introduced to Dr. Vegapunk and learn more about what Devil Fruit actually are and what awakening entails before that option becomes available to Luffy.
This also has a potential ‘power scaling’ problem; I’m not big on power scaling debates, but I do still think there’s a clear difference in how Oda depicts Luffy vs the overwhelming power of the Emperors, who more akin to a force of nature – someone like Whitebeard, Kaido, or Big Mom. I’m not sure Oda’s ready to put Luffy on that level quite yet as it may undercut some of the narrative tension going into the later battles against Shanks and Blackbeard. In theory, Gear 5 or Awakening only powerup Luffy. So ultimately, any allies in the fight would be entirely ancillary – it would be Luffy’s decisive victory.
The very reason we’re having this discussion, the reason there is this perception that Luffy needs a major boost in strength, is because Luffy’s struggling to damage Kaido even with the help of 4 allies and the things he learned from Hyogoro and Katakuri. It seems implausible Luffy would climb, on his own, to face Kaido one-on-one in such a short timeframe, even with Gear 5 or awakening.
The battle between the five Worst Generation Pirates and the two Emperors is going better than expected, but they have been focusing all of their efforts on attacking Kaido without even worrying about Big Mom. This has allowed Big Mom to play offense while Kaido plays defense. I don’t think there’s any way this ends well unless Big Mom is either drawn away from the roof or betrays Kaido, leaving Wano altogether (Maybe once she finds the Road Poneglyph).
It’s important to remember Toki’s prophecy foretells nine allies – and right now there are only five worst generation pirates on the roof. There are many possible allies to fill out their ranks down below – Marco, Yamato, Momo, Hiyori, and, if my suspicion is accurate, Gecko Moria may be among those who join in the battle against Kaido.
Moria’s Revenge
We last saw Moria in chapter 925 invading Blackbeard’s fortress on Pirate Island, outraged at the apparent death of his subordinate Absalom. We learned on Thriller Bark that Moria’s entire crew, whom he cared about deeply, were killed by Kaido. Moria never lost his ambition to become Pirate King, but created an army of undead zombies after his crew were killed, afraid to lose more people close to him.
Blackbeard appeared intent on recruiting Moria rather than killing him, which seems like a hard sell after killing Absalom, but what’s the one thing that could sway Moria to join Teach? The promise of vengeance against Kaido. We know Teach is interested in harvesting powerful Devil Fruit – he sent Burgess to Dressrosa for that very reason. Teach appears to be headed off in pursuit of something else, but I could easily imagine Moria agreeing to join Teach on the basis that some of the Titanic Captains, like say, Shiryu are deployed to Wano to fight alongside him against Kaido. Teach gets to harvest some Devil Fruit and Moria gets his vengeance. Oda again reminded us of Moria during Oden’s flashback in Act 3 – it’s clear he wants us to remember Moria.
Right now Onigashima is in the sky, but it has to come down eventually and I can easily imagine a scenario where Moria arrives when the battle reaches an inflection point.
Toki’s prophecy foretells Nine Shadows striking down Kaido and Moria just so happens to possess a Devil Fruit which allows for the control and manipulation of shadows.
Thriller Bark: Beginnings of the Current Story Saga
It’s important to note just how many narrative elements of the current story saga were first introduced during Thriller Bark. Gecko Moria was introduced and we learn Kaido’s name for the first time. Samurai Ryuma and Shusui are introduced and we first hear about Wano Country, the Land of Samurai, in the New World. Charlotte Lola, Big Mom’s daughter, is introduced, and forms a bond with Nami, promising her mother will someday assist Nami on her voyage. We are also introduced to the ‘Continent-Puller’ Oars who bears a striking resemblance to Onigashima.
Thriller Bark just so happens to take place immediately following the introduction of the concept of the ‘Four Emperors’ in chapter 432. We can, to an extent, gauge which ideas, characters, and concepts are interrelated based on the proximity with which they are introduced in the narrative. I can easily imagine Oda planning for Moria to play a critical role in Kaido’s defeat from the time he was first introduced.
As he collapses, Moria tells Luffy to go on and face the ‘real nightmares’ in the New World, again thematically connecting Nightmare Luffy to the ‘Dream of Wano’, the ghosts of the Akazaya Samurai, and the battle against Kaido.
Further Evidence
Perhaps hinting toward the role this form will ultimately play, Nightmare Luffy wielded a large Katana. We’ve never seen Luffy wield a Katana before Thriller Bark. Again, in Act 1 of Wano, Luffy was running around with Nidai Kitetsu. Swords are regarded as vessels for the soul or will of those who carried them in Wano and thus wielding a sword to strike down Kaido will both echo Ryuma’s defeat of a Dragon and serve as a physical / tangible representation of Wano and Oden’s will.
It seems like the ideal solution; There’s a clear difference between one person hitting with he force of nine and nine people hitting with the force of one. I believe there’s more going on with Kaido beyond the durability of his skin. I won’t go into too much detail here, but I have talked about the theory that Kaido’s inability to be killed is, in part, derived from incredibly good fortune (for more on this topic, Kaido: Secret of the Koi / Dragon Devil Fruit
).
That said, Kaido is certainly the real deal and is incredibly powerful. His greatest asset in battle appears to be his durability and so breaking through his defenses will be critical in achieving victory. Putting the force of all nine Akazaya Samurai (or all 9 of Luffy's worst gen friends / allies) behind Luffy's punches would certainly seem to be more effective than nine people independently beating up Kaido.
Nightmare / Dream Luffy allows for the defeat of Kaido without permanently powering up Luffy to the level of Emperor. In the eyes of the World Government, Luffy will be credited with Kaido’s defeat as the one to deliver the finishing blow, but we, as the readers, will know this is a form Luffy cannot access naturally and as such, still has room to grow through Awakening, Gear 5, etc. in the future when he faces Shanks and Blackbeard (and maybe Big Mom again).
I do think there's a chance that there's nothing to the 'Nightmare' / 'Dream' Luffy idea, as much as I love the idea of the Scabbards still playing a role, in which case a group of nine taking down Kaido does seem to be the most likely alternative. We've got 5 - and I honestly can't see Apoo and Hawkins turning on Kaido. If they did, it just wouldn't feel satisfying. I think Hiyori will be involved in striking down Orochi (Ame no Habakiri is still in her possession). I do think Momo could partake symbolically, leading the charge, and stepping into his father's shoes. Yamato did tell Momo that he is going to be in part responsible for the New Dawn. I still think it makes a lot of sense for Moria to make his way to Wano. It just seems like very suspicious timing that Oda would update us on Gecko Moria in the middle of Wano, between Acts 1 and 2, when he was last seen right after Marineford. Marco is another possibility, but then, we're left without someone to battle King and Queen other han Sanji. It seems like Drake might have some personal vendetta against Kaido, so if we learn more about his backstory, he could join the fight on the roof, but it seems a bit odd he hasn't done so already if that was Oda's intention. It actually took some work to split Drake off from the group going upward. I don't really think it would be particularly satisfying for Apoo and Hawkins to flip sides now and honestly, 8/9 being Supernovas with 1 random character thrown in would feel a bit off.