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In this thread I will be taking a look at some interesting parallels between the Thriller Bark arc and the current Wano arc. Sometimes finding similarities in past arcs can help when predicting/theorizing events that have yet to happen.
First let’s look at how the dynamic between Orochi/Kaido is like Hogback/Moriah.
Hogback’s medical genius enabled Moriah to amass an incredible amount of corpses that were suited for battle. With his skill he modified the body of a normal girl, Cindry, into a capable warrior.
Hogback’s medical genius enabled Moriah to amass an incredible amount of corpses that were suited for battle. With his skill he modified the body of a normal girl, Cindry, into a capable warrior.
Orochi plays a role like this for Kaido. As shogun he is able to be the face that meets with the WG/Cp0 which frees up Kaido to make moves in the underworld (SMILEs). Also, the stockpile of money/weapons Orochi provided was another pivotal contribution to Kaido’s war plans.
Kaido and Moriah both value the strength of their underlings heavily, seeking out anything that would help them achieve this goal.
Kaido - SMILEs and breaking the wills of mighty soldiers
Moriah - gifted shadows and legendary zombies
Kaido - SMILEs and breaking the wills of mighty soldiers
Moriah - gifted shadows and legendary zombies
Likewise, Moriah and Kaido are no stranger to using underhanded tricks to gain any advantage they can get. Luffy and Oden dealt with these tactics firsthand when fighting against them. Usually these tricks are made possible by unique Devil Fruits like the Mane Mane or Horo Horo.
Kaido’s top commander is King, a swordsman who is of some rare race.
Moriah’s top zombie is Ryuma, a swordsman of legend from Wano.
We first hear of Wano in TB, and Ryuma’s significance to Wano was established along with Shusui’s.
Moriah’s top zombie is Ryuma, a swordsman of legend from Wano.
We first hear of Wano in TB, and Ryuma’s significance to Wano was established along with Shusui’s.
Speaking of firsts, we hear Kaido’s name for the first time in TB and get our first bit of foreshadowing for BM through Lola. Was also the first arc to ever have an antagonist of equal standing show up at the end of the arc. In TB it was two warlords, now in Wano it’s two yonko.
Even the antagonists themselves have some similarities. Their reputations were on the line against Luffy, Moriah was in danger of losing his Warlord position and BM allowed Luffy and crew to come in and steal her poneglyph and dip without much consequence.
Kuma was honorable and kept his word with Zoro, Kaido seemed to have developed into an honorable man after his experiences with Oden in his final moments. Kuma/Kaido also compromised with Zoro/Oden by giving them a seemingly impossible trial to endure.
That about wraps up the parallels I found the most intriguing between the two arcs. And if I could take anything away from this I beleive that we are in store for another unreal moment of sacrifice from Zoro this arc, likely when facing down Kaido as he once did Kuma. But-
-rather than being forced to lay down his swords, I believe he will emerge victorious in combat, kill Kaido, and gain full recognition for his actions instead of them being kept secret as they were in TB. 
