Kai arranges a fight with the power-mad Aichi before it's too late. As the two square off in an alley, Kai recalls the last time he encountered the power of PSYqualia... years before, when he was Ren's friend and teammate!
Kai heads to the Underground area to await his fateful match with Aichi. Back at home, as Aichi reviews his Shadow Paladin deck, he receives a PSYqualia induced summon from Ren who is waiting for him at Card Shop PSY. Aichi, led by Ren's PSYqualia summon reaches as far as outside the Card Shop when Kourin suddenly rides up throws him a helmet & tells him to come with her. Back at the Underground area, Miwa shows up with Misaki & Kamui who both implore Kai to face Aichi in a Vanguard fight and help bring him back to normal. Just as Kai informs them that that is exactly why he is here, Kourin immediately arrives with Aichi. Miwa, Kourin, Misaki & Kamui clear the area to watch the fight from a distance. Kai upsets Aichi when tells him that he still thinks he is weak & Aichi vows to prove his strength to Kai as they get ready to begin their fierce battle. Aichi is startled when he realizes Kai is going to fight him with his former Royal Paladin deck. Kai vows to show Aichi the "true power" of the deck that he threw away which rattles Aichi even more. Aichi goes first & uses his units' skills to add Blaster Dark who he refers to as his avatar from his deck to his hand. Kai has a flashback of losing his parents 4 years ago & meeting Ren from his new school & later Tetsu (after he leaves town to live with his uncle). Tetsu loses to Kai in a Vanguard card fight & he and Ren tell tell Kai of Foo Fighter. They recruit Kai & they have a love of fun until one day Ren's PSYqualia powers awakened. He beat Tetsu repeatedly claiming that he was now the "strongest fighter" ever. Ren abandoned the idea of him, Tetsu & Kai being Team Foo Fighter & has construction begin for the new Foo Fighters Headquarters where only the best fighters would be selected. Kai realizes that Ren has become obsessed with power and refuses to go along with his new plan & quickly challenges him to a card fight. The match is fierce and as Ren announces his "Final Turn" he taunts Kai but before he can claim victory his overuse of his PSYqualia power causes him to collapse. Kai catches him in time but Ren is still fixated on how much stronger he's become. Kai quits the team & moves back home peeved about how powerless he was to stop Ren. He reminisces on how refreshing after all of this it was to meet Aichi again and of how much fun Aichi made him remember Vanguard fights to be. He also remembers how fixated Aichi had become on "getting stronger". He vows to himself that while he couldn't stop Ren, this time will be different. With stern determination to accomplish this, Kai draws & uses his units' skills to add Blaster Blade from his deck to his hand. Kai reminds Aichi that then & now his avatar is not Blaster Dark as he claims but will always be Blaster Blade. Kai faces Aichi thinking that this time he's going to teach him what true strength is & declares that he is going to stop him!