Hi In Chapter 924 i think we've been smartly mislead by Oda. Now look at this: The guards don't know who's inside that cell. In fact, they're not even sure if somebody's there, which means that the Mysterious Prisoner has been imprisoned there for a very long time, before those guards started working there. Luffy was walking towards his cell, and this happened: Ever since the chapter came out, my understanding of this page was different from what the majority of the readers believed. People say that the guard was about to hit Luffy and the mysterious prisoner saved him. I see otherwise. Luffy was walking towards his cell, he suddenly glared at something in the right. He did NOT glare at the guard, but at the mysterious cell. He sensed something about it. Probably a big threat, considering his shocked stare. The prisoner did not attack the guard. He attacked Luffy, but the guard was in the way so he got hit by accident. Look at Luffy in the panel above. The mysterious cell is on his right hand side. The guard is standing right between Luffy and the prisoner. Oda even gave us another camera angle to make things clear: Look at this panel above, imagine Luffy's position right before the guard was hit. He was forming a line along with the guard and the prisoner. That's why the guard got hit instead of Luffy. Oda never wastes a panel. In all of the +900 chapters, i've never seen a panel dedicated for Luffy glaring like that at an ordinary guard, it makes no sense. Still not convinced, alright read this panel carefully: People think that Luffy glared at the guard because he threatened him. But wait a minute. The guard says: " the way you're looking at me ... " , which means Luffy was glaring at his right hand side even before the guard addressed him. Why, out of all the guards there, Luffy chooses to glare at the one who is standing right between him and the mysterious cell ? It can't be. Luffy was definitely staring at the mysterious prisoner, and the guard thought Luffy was looking at him because he was simply standing in front of him. Luffy also has a speech bubble in that panel, just like the prisoner's. Luffy might have seen the future using his Observation Haki and he felt the attack, but luckily for him, the guard was there and he got hit. Oda purposefully mislead us in that Chapter because he wanted us to think that the prisoner saved Luffy, that he's a future ally. Because if we think like that, then we conclude that the mysterious prisoner is NOT the Lurking Legend. " i'll introduce a legend that's been laying dormant in the One Piece world. The greatest enemy ever for Straw Hats will hinder their way. " - Eiichiro Oda I personally think that the mysterious prisoner is the lost captain of Kaido and Big Mom, mentioned by Hina in Chapter 907. His imprisonment has something to do with Big Mom and Kaido's past. They might have betrayed him using some tricks, and put him there. 1- the Rocks captain disappeared a very long time ago, the prisoner was there for a very long time considering how not even the guards know about his existence. 2- We know that his name or his group's name is Rocks. The mysterious prisoner is imprisoned in a rock mine. Coincidence ? ( Viz's translation is Rox, but it's simple translation, just like they put Ushimitsu Kozo instead of the Witching Hour Boy. Jaimini's translation was Rocks, MangaStream's was Locks ) 3- Luffy sensed a major threat, considering his glare and the panel dedicated to it. So the prisoner is definitely strong. 4- The prisoner is definitely not Kawamatsu, and not Denjiro. Why ? Because if he was one of them then Kaido would either kill him or try to break his will, just like he's doing to Luffy and Kid. The second option is impossible, because he's ordering them to feed him poisonous fish unlike the other prisoners who are being fed mochi, thus he's trying to kill him. Why would he try to kill him if he wants him to join his crew ? Which means that Kaido wants him dead at any cost, but he can't kill him in person. Kaido wants to stay away from him. The only solution is to give him a poisonous fish per day in hope that he dies. But he still didn't die, tells a lot about his strength. Let me explain it very simply : We have Kaido, and we have a prisoner. Now if the prisoner is weaker than Kaido, then Kaido has 2 options: kill him or try to break his will just like he's doing to all the other prisoners. Surprisingly, Kaido is doing none of these 2 options. Instead, he's trying to kill him without having to face him. And you know what that means ? It means that the mysterious prisoner is stronger than Kaido.