Issei voices out his intention to meet Vali while Rossweisse tries to dissuade him from doing so due to Vali being a part of the Khaos Brigade. Issei, however, refutes back saying Rias is important to him therefore he is willing to risk anything to save her. Finally giving in, Sirzechs decides to leave Rias' rescue to Issei and his friends. Issei and Koneko are later seen in the destroyed old school building of Kuoh Academy, waiting for Kuroka to come while their friends wait back at the Hyoudou Residence. Kuroka eventually arrives and demands Koneko back as a term for meeting Vali. Issei refuses and tries to ask for another way. Irritated by Issei's persistence, Kuroka ask Vali out to deal with Issei personally, revealing that Vali, Arthur and Bikou has been watching from the start. Issei proceeds to ask Vali to help him reach the Dimensional Gap but is tested by Vali who questions Issei on what he will do if he rejects him. In response, Issei summons out his Boosted Gear, saying that he will use force if needed. Pleased with his answer and determination, Vali gives the order to Arthur who reveals his family's prised treasure the Holy King Sword, Collbrande, and it's ability to control and cut through dimensions. Before leaving, Azazel hands the Down Fall Dragon Spear to Asia, saying that it will protect her when needed. With the preparation complete, Arthur cuts through the dimension and brings the protagonists to the Dimensional Gap. Happy to see Rias again, Asia tries to approach her until Akeno notices Rias trying to attack Asia and rescues her in time. Left with no option, the team decides to suppress Rias first for her safety. In retaliation, Rias releases a powerful surge of Power of Destruction, deflecting all of their attacks at the same time. Issei begs Rias to stop as Koneko notices Rias responding to their voices. They immediately starts talking to Rias attempting to bring her back to her senses and successfully reach her until the cursed fragment of the Scale Mail corrupts Rias' body. With Rias fully taken over, she starts attacking her friends fiercely. Akeno begs Issei to rescue Rias by fighting her as he is the only person capable of doing so. Initially refusing to do so Issei enters his Balance Breaker, and proceeds to battle Rias as their clash destroys the field created by Arthur forcing the others to return to the human world while Rias and Issei continue their battle.