Binks Sake says after Rising Sun, The Moon will come
And according to Toki's Prophecy, Moon will cast Nine Shadows who will save Wano
Sun God Nika is also described as God who makes others Happy or Laugh
And this is similar to Kaidou who made Laughing People through Smile Fruits (Kaidou is portrayed as Fake Joy Boy)
This is why i believe that Kaidou is gonna be taken down by Joyful Army
I think Luffy won't be the one to finish off Kaidou, but there will actually be a Scene where Alliance are all standing up together facing Kaidou
In Thriller Bark, after Luffy used Nightmare Mode & reverted back to Normal, we saw all SHs combined their Efforts to hold Oars in place & then Luffy finished him off. In Kaidou's Case, i believe Luffy will be the one to restrict Kaidou & make him unable to counter the Attacks of the Alliance as they all engage him while joyful & laughing then comes a Team Combo from all SHs which ends with Zoro dealing the Final Blow himself alone
I believe what Denjiro is about to do gonna make all Beasts Pirates lose & Samurai Victorious (Only Kaidou remains)
All SHs, Kid, Law & Killer, Marco, remaining Scabbards, Hyogoro, Carrot ... etc are all doing nothing now so i believe Oda is preparing a Scene where they all stand together in massive Double Spread, to show Sun God's Biggest Ability which is the Allies he gains