Oda has made it pretty clear that Kaido is the strongest in the series, but many act like he’d get stomped by Prime Rayleigh/Roger/Whitebeard/Garp/Oden/Shiki etc. In my opinion, Kaido is the 4th strongest pirate to ever exist (after Rocks, Roger and Whitebeard). His bounty is literally the 3rd highest ever known.
Kaido is one of the best Haki users in the verse currently. He probably has the strongest Zoan devil fruit.
His body is inherently strong and durable. He has immense raw strength and arguably the best durability in One Piece. I read through chapters 987 to 1010 again and here’s some stats:
- Kin’emon, Denjiro, Ashura Doji, Inuarashi, Kawamatsu and Kikunojo stabbed him in the abdomen and through his hand in ch. 987
- Izou shot him in ch. 987
- Nekomamushi twisted his arm in ch. 987
- Raizo cut his throat in ch. 987
- The Scabbards slammed him into the floor in ch. 987
- Kin’emon cut his mouth in ch. 991 with “Flamerend”
- Nekomamushi hit his jaw in ch. 992 with “Crimson Cat Dance”
- Inuarashi stabbed him in the abdomen in ch. 992 with “Canine Scourge”
- Kawamatsu cut his mouth in ch. 992 with “River of Sea”
- Kikunojo and Izou combined “Fallen Snow Scythes” and “Slicing Rounds” in ch. 992, causing multiple cuts along Kaido’s throat
- Raizo’s set Kaido on fire with “Bolo Breath Restoration” in ch. 992
- Inuarashi, Kin’emon, Denjiro and Ashura Doji used “Togen Totsuka” in ch. 992, cutting along his existing scar