Kaido is currently one of the strongest characters in One Piece, if not the strongest. One of the Four Emperors of the Sea, Kaido was once an apprentice on the ship of the legendary Rocks D. Xebec. After the God Valley Incident, he went on to make his own crew and rose to the top all through his sheer strength alone.
In time he became a Yonko and gained an incredibly high bounty of 4,611,100,000 berries. Kaido has been in several battles in his life and while he's lost some of them, what's impressive is that he's survived all.
9 Kaido Vs The Roger Pirates & The Marines — Just like every other member of the Rocks crew, Kaido lost this battle
Kaido is one of the many characters who took part in the God Valley Incident in One Piece. Being an apprentice on Rocks' crew, Kaido fought the joint force of the Roger Pirates and the Marines.
Together, the Roger Pirates and the Marines succeeded in breaking apart the Rocks Pirates and successfully put an end to the crew on God Valley. Just like every other member of the Rocks crew, Kaido lost this battle.
8 Kaido Vs Gecko Moria — As expected, the victor was none other than Kaido
Around 23 years before the current story events, Kaido finally clashed with Gecko Moria in Wano Country's Ringo region. During this time, Moria was quite powerful and one of the most impressive new generation members in the New World.
In an intense battle that lasted for a while, Gecko Moria lost to Kaido and his entire crew is known to have been slaughtered. As expected, the victor was none other than Kaido.
7 Kaido Vs Kozuki Oden — thanks to Kurozumi Higurashi's distraction, Kaido struck a decisive blow to Oden & won
Three years after the fight against the Gecko Pirates, Kaido was faced by Kozuki Oden and his nine retainers, known as the Akazaya Nine. The fight between them lasted days and Kozuki Oden's strength stood out even against Kaido.
Towards the end, Oden started to overwhelm Kaido and would've killed him had Kurozumi Higurashi not intervened and distracted Oden. In the meantime, Kaido struck a decisive blow to Oden and won.
6 Kaido Vs Shanks — fans know that Kaido retreated eventually & Shanks arrived at Marineford unscathed
Shanks and Kaido are two of the Four Emperors of the Sea currently and they clashed shortly before the Marineford arc of One Piece. The two met when Kaido was on his way to intercept Whitebeard and prevent him from saving Ace.
Shanks stepped in and the two are known to have fought across the New World. Who exactly won this fight isn't known, however, what fans do know is that Kaido retreated eventually and Shanks arrived at Marineford unscathed.
5 Kaido Vs Kid & Killer — Kaido won the fight, Kid was locked up in Udon prison, & Killer was made into Orochi's personal dog
Kaido ambushed Kid and Killer in Chapter 795 of One Piece, where he made his debut. After Hawkins switched sides and Apoo was revealed to have betrayed them, Kid and Killer fought Kaido, however, they got severely injured.
As expected, Kaido won the fight, and Kid was locked up in Udon prison. Meanwhile, Killer was made into Orochi's personal dog and force-fed a SMILE Devil Fruit.
4 Kaido Vs Monkey D. Luffy — Luffy failed to damage Kaido & was defeated in one shot by Kaido's Thunder Bagua
Kaido and Monkey D. Luffy fought in Wano Country's Kuri region in the first Act of the Wano Country arc. After attacking the alliance, Luffy was infuriated with Kaido and decided to attack Kaido head-on, abandoning the plan in the process.
Despite throwing everything his way and even going Gear Fourth, Luffy failed to damage Kaido and was defeated in one shot by Kaido's Thunder Bagua. Consequently, he was thrown into Udon Prison where he met Eustass Kid and later staged an uprising.
3 Kaido Vs Charlotte Linlin — Big Mom managed to hold Kaido to a draw quite easily & the battle ended in a tie
After arriving in Wano Country, Big Mom found herself being captured by Queen and taken to Onigashima. There, Kaido fought her in a battle that went on for the entire night.
Since Big Mom is just as strong as Kaido, she managed to hold him to a draw quite easily and the battle ended in a tie. Afterward, in a surprising turn of events, Kaido and Big Mom ended up making an alliance to destroy Monkey D. Luffy and then take the One Piece.
2 Kaido Vs Akazaya Nine — The battle ended in Kaido's favor even though the Akazaya Nine tried their hardest
In the climax of One Piece's Wano Country Act 3, Kaido and the Nine Red Scabbards of Kozuki Oden finally began the long-awaited fight on the roof of Onigashima. Due to their Ryou, the Akazaya Nine were able to inflict several injuries on Kaido's body and weaken him slightly.
However, Kaido, being the monster that he is, managed to take down all of them effortlessly once he got serious. The battle ended in Kaido's favor even though the Akazaya Nine tried their hardest.
1 Kaido Vs The Worst Generation — Since the fight is ongoing, the result remains unknown
A currently ongoing fight, Kaido finally took on the Worst Generation after the fight against Akazaya Nine. In this clash, he is backed up by Big Mom, another Yonko. The opposition includes Luffy, Law, Kid, Zoro, and Killer, some of the most prominent members of the Worst Generation.
Surprisingly, all of them have the ability to hurt Kaido in one way or the other and they're putting on quite a good fight for now. Since the fight is ongoing, the result remains unknown at the moment.