Why did Kuzan joined Blackbeard pirates?? | One piece #anime #shorts

do you know why Kuan joined the Blackbeard Pirates while no official statement has been given fans have started to give out their theories about this some say it was because kuzan wanted freedom from any interference from the Marines and also wanted a strong and powerful position While others say that he is still loyal to the Marines and is working as a spy in the Blackbeard Pirates helping the Marines by telling them every move that teach makes this situation is much similar to Drake who SPI on kaido while some also say that he wants to lead the Blackbeard Pirates to the one piece to know about the void Century however as always these are only theories and cannot be always true