According to the search results, Kaido was defeated by Luffy in the Wano Country Saga of One Piece. After being hit by Luffys strongest attack, Kaido was thrown underground and landed in a pool of magma. The fate of Kaido and Big Mom remains unclear, but it is likely that they are alive, albeit in a very bad physical condition. The volcanic eruption that occurred after Luffys victory may have sent them out of the country. Some fans speculate that Kaido may have found a way to survive, while others believe that he died. However, the creator of One Piece, Eiichiro Oda, reportedly hates drawing death scenes and killing characters, so it is unclear what happened to Kaido. In any case, it is confirmed that Big Mom was killed by Blackbeard.