After Joker was captured, he was thrown directly into Impel Down. As a heinous criminal who had attacked Mary Geoise, he was naturally sent to Level Six of Impel Down.
Not only that, Sea Stone shackles were wrapped around his limbs and neck. Even as a Chop-Chop Fruit user, he should theoretically have had no way to escape under such circumstances.
However, Joker had prepared long ago. Before Garp captured him, he had split off his wrists, ankles, and neck, then replaced them with the body parts of someone who had never eaten a Devil Fruit.
Thus, those Sea Stone shackles had no effect on him whatsoever. Whether by using his Chop-Chop Fruit abilities or his own Armament Haki, he could easily break free.
In fact, Joker escaped almost immediately after entering Impel Down. Freed from the restrictions of Sea Stone, he effortlessly split apart his body, slipped through the prison bars, and even conveniently stole a guard's identity.
Using the Chop-Chop Fruit, he stripped away the guard's entire skin and draped his own skin over the guard. Then he separated part of the guard's brain tissue, erased the guard's personal consciousness, disassembled him and sent him into the cell, then pieced him back together. The fake Joker was born.
The reason Joker had not left over the past few years was because he wanted to slowly corrupt the other guards and some of the prisoners within Impel Down. He sincerely wanted to turn all of Impel Down into his base of operations.
After all, this place was full of talent. Whether prisoners or guards, everyone had more or less some psychological problems. The seriously afflicted were only a step away from madness. Here, he even felt as naturally at home as a fish in water.
The prison was full