The World is Vast and InfiniteUsing the equipment Mitsuki and Grummen designed together, the gate is opening. Kark stops the Church member and Chihiro agrees to fight him, knowing that's what Kark wants, and the other three go on to save Tokyo. Kark lets them go. Using the people below, Kark summons Jormangandr, the serpent who eats the world, to fight him. Dux appears behind the other three and states the mansion they are looking at is where Mitsuki and Grumman once conducted their research and their goal. Chihiro struggles in his fight but goes berserk to wound Jormangandr. However, he is stabbed by Kark before and knocked to the ground. While unconscious, he has a vision of his own death. Dux asks how he would like to die, showing him four different ways he previously died: slashed by Jun, stabbed by the half-familiar Inuki, strangled by Kakihara, and he and Yuri killing each other. She reveals the dreams were his memories and this "play" has been performed many times before. The events change but the end is the same, with the dreams a warning to keep him from making the same mistakes. At the end of each play, Chihiro uses his power as Lord of Vermilion to start it over again in a new world, seeking forgiveness he is never given. Dux wonders if he can change the script and Chihiro vows he will. The number of familiars blocking the way are endless, so Tsubaki and Kotetsu offer to hold them off while Kurome goes ahead, knowing they need to save Tokyo. Grummen sends Chiyu to kill Kurome, even though leaving her increases the chance the gate goes out of control. If the gate is closed before he sees Mitsuki, he will lose everything. Chiyo disagrees and says he tries to manipulate everyone, her Yuri, Mitsuki, by saying he loves them, even though his love is only for himself. Chiyu tells him Mitsuki never loved him, and even if he opens the gate, she won't return to him - just her family. Kurome breaks in but is ignored, Grummen declaring he won't believe it and leaving. Chiyu has no need to see how this ends, but is curious and fights Kouma.
Chihiro fully enters his Lord of Vermilion state, allowing him to defeat Jormungandr, a god who brought a world to end. Kark declares his existence is an affront to the gods of death as Chihiro cuts through his familiar and slices off his hands before killing him. Tsubaki and Kotetsu are being worn down by the sheer number of familiars, but Julia and Suruga arrive and help them, as they exist to protect Tokyo. Kurome and Chiyu fight, damaging the machines controlling the gate. Without the machines, the gate spirals out of control, fully opening and incinerating the mansion. Grummen declares he is coming for Mitsuki and Drail shoves him into the gate to speed him along. Out of control, the gate will eventually consume the world. Chihiro intends to use his status as the closest candidate to the Lord of Vermilion to close the gate, only for Yuri and Jorumngandr to stand in his way. He does not want to kill her again but Yuri intends to kill him herself to save him from becoming the Lord of Vermilion. Yuri and Chihiro charge each other and it looks like the final scene of the last timeline will be repeated, only for Chihiro to fly by and kill Jorumungandr, as he says he could never kill Yuri, who is so precious to him. Yuri realizes he hasn't changed after all and apologizes. Drail leaves, disappointed. Yuri and Chihiro seem to enter the gate together, only for Chihiro to push Yuri away and enter alone, telling Yuri to live. The gate closes, swallowing Chihiro.
Yuri, Tsubaki, Kotetsu, Akira, Haru, Kurome, and Chiyu move into Chihiro's childhood house and begin working together to find a way to open the gate and bring him back. Julia and Suruga are seen patrolling Tokyo, killing leftover familiars, when Suruga is approached by a smiling Drail.
