User blog comment:Kaido King of the Beasts/Why Just Have Two?/@comment-24850639-20150428212348/@comment-24769684-20150428224151

I don't think Blackbeard would have killed Jozu during the timeskip (he may not need to kill Jozu to steal his powers, but this is a foggy area). Besides, since Jinbe was so affiliated with Whitebeard, I think he would know if Jozu had his powers taken by Blackbeard.

The rest of the theory sounds cool, however I still doubt Blackbeard ate a Cerberus fruit. It couldn't be that simple, since if Marco ate two Devil Fruits, wouldn't his body just be able to regenerate after destroying itself by that Logic? I don't think Luffy and co. would have felt so strange about Blackbeard's body if he were just a Zoan. If that were the case, they'd feel weird about all Zoans, including Chopper.

Mihawk being defeated by an opponent other than Zoro would be an intriguing plot twist that I've certainly considered before, and it wouldn't be too strange for Oda to do that. It would certainly make things easier for Zoro in the Final War, as I hope he is able to take on an Admiral at that time (revenge on Issho!), rather than just a Shichibukai.

And I know this is totally baseless, but I think Blackbeard will kill Shanks, who will be the only one to stop him from reaching Raftel after Big Mom and Kaido have been defeated. Like the time Luffy got kidnapped by Higuma, this'll be sort of Luffy's fault again, but Shanks won't blame him for it, only telling him to reach the finish line and become the Pirate King. Then the Straw Hats will face off against the Blackbeard Pirates, with Luffy having both Ace and Shanks as martyrs to avenge and will beat Blackbeard to a pulp.