Mukuro Rokudo explains that there's only one person who would be able to steal his body, who is Demon Spade, much to everyone's surprise. He continues by explaining that Demon got his hands on Chrome Dokuro first to lure out his soul from his body and then intentionally lost their duel so he could possess now his empty soulless body in Vindice Prison. Reborn says that he never heard about an illusionist's body being possessed by another illusionist while possessing someone. Mukuro agrees to this since it's an exceptionally difficult technique and not to mention that Demon had just obtained it recently.
Chrome remembers that Demon had been waiting for the perfect moment, with the awakened Simon Ring, he confidently battled Mukuro, realizing everyone that he managed to achieve that feat because of the power of Simon Desert Ring. The Vindice appear, making Enma think that they intend to take Julie Kato and him since they have lost. However, it turned out that the Vindice have to put that aside because an urgent situation is occurring; Demon who had possessed Mukuro's body gone berserk and destroying their prison and it's only a matter of time for the jailbreak to occur. The Vindice demand Tsuna and the others to deal with Demon, even though they are actually able to deal with him, because long ago and even now, Demon Spade's actions are done for the name of Vongola.
Tsuna agrees in exchange that the battle between Vongola and Simon being negate and that the Vongola and Simon members who are imprisoned to be freed if they able to defeat Demon, to which Enma agrees. The Vindice agree and promise that they will free the imprisoned members if they managed to defeat Demon. One of the Vindice reveals himself to be the one who witnessed Giotto and Simon Cozzato's oath in the past. Just then, the group is interrupted by a sudden attack that destroys their surrounding and is powerful enough to exhaust Yamamoto and Gokudera's flames as the two protect the group from the impact. A combustion of energy appeared in front of them, Bermuda realizes that Demon has obtained the same attribute as theirs. From the black portal, Demon reveals himself with Mukuro's body and states that it's about time to end the generation of Tsuna's Family.
*Note: Bold + Italicized = First Appearance