Yu and Mika arrive to rescue Shinoa Squad and Narumi. They fight for their lives as human and vampire armies wage war around them. As they escape, they are shocked to run into Guren. Guren greets Yu and then attacks him, but Mika blocks the attack.
Kureto tells Guren the experiment is beginning. Mirai Kimizuki floats into the sky and is struck by chains and bound by the demon Abaddon as the blood of humans, progenitors, demons, and seraphs are offered to her. As her brother Shiho Kimizuki recognizes her and becomes enraged, Guren stabs him in the back.
Horrified, Yu moves to attack Guren but hesitates and demands an explanation. Tears drip from Guren's eyes as he warns Yu to run. Immediately afterward, he cuts Yu deeply through the chest, making Yu collapse and gasp for air as blood drips from his mouth. Mika carries Yu to where Krul is waiting for him, and she says Yu will heal once he drinks her blood.
In his desperation to save his family, he ignores Asuramaru's warnings and blows the trumpet waiting within his mind. He is consumed by an immense power that splits the skies.
Yu and Mika step into the fray, surprising Shinoa Squad and Narumi. Mika points out that humans are killing humans and tells Yu they should not have come there, but Yu disagrees. Yu asks Shinoa for orders. She issues a retreat. The survivors all request to be backup for the rear guard, but Mika says he can block chains at that speed on his own. Yu chides Mika on teamwork. When Mika asks Yu if he expects him to trust humanity after seeing them sacrifice their own soldiers like that, Yu says that he is only telling Mika to trust him.
Kureto notes that three of the surviving soldiers are Guren's soldiers with the black demons. Chains erupt out of one of the trucks. Mika, Yu, and Shiho Kimizuki block them. Kureto says the black demon wielders have matured and muses having them for himself but says that their owner will dispose of them.
An army of vampires arrive, cursing the insolent humans for their recent attack.
Kureto summons his own army and orders them into battle to buy time for the experiment to be completed.
The vampires and humans wage war. Shinya shoots vampires near Yoichi and says he and Ichinose Squad will back up the children. He orders them to run. Fighting through their enemies, the children flee. Shiho Kimizuki warns Yu that he has run too far ahead.
Guren walks onto the battlefield, sword in his hand. Yu is delighted, and the surviving Moon Demon Company members are shocked. Guren greets Yu and suddenly swings his sword at him. Mika intercepts it, surprising Yu. Guren tells Mika that he is in the way.
Kureto announces to Guren that it is time to begin.
Guren raises up his sword, and chains wrap around his arm as the curse consumes him. Mika tells Yu to run and says Guren has betrayed them. Yu disagrees. Shinoa also tells them to run since Guren is not acting like himself. Guren mentions drinking the blood of the sacrificial humans, the blood of demons, the blood of progenitors, and the seraph of the end. When he swings his sword, he slaughters both a vampire and a human. The chains release him and return to the van.
Kureto warns Aoi that Heaven will smite them, but they will take that power and control it. He orders his soldiers to bind the seraph completely.
Mirai Kimizuki erupts from the van and floats in the sky. She has four large, feathered wings and a single long trumpet before her. Her eyes are dark with peculiar markings on her irises. She curses the sinners and says ruin will fall down upon them. Shiho Kimizuki recognizes her, shocked and horrified.
Chains erupt from the remaining van and pierce through Mirai, making her scream in pain as a magical circle appears behind her.
While Shiho is enraged, Guren stabs him from behind. He tells him to hold still because they have not yet offered enough blood to control Mirai. Yu races to Guren and swings his sword at him but hesitates. Guren calls Yu a "little wuss" and asks why he stopped. Yu cannot believe what is happening and wants Guren to explain himself. He asks if they were Guren's family. Tears escape Guren's eyes, and he whispers to Yu to please run. Relieved, Yu smiles until Guren swings his sword down and deeply wounds him.
Yu collapses, gasping for air as blood drips out of his mouth. His wounds are too deep. While Mika and Shinoa Squad panic, Guren whispers to himself that he must continue to sleep or else this will scar him for the rest of his life. The curse marks reappear and cover half of his face (Mahiru is the one who is possessing him).
Up above, a black aura appears from Mirai's back. The soldiers announce that the fifth trumpet is transforming into an angel of destruction to smite mankind. Although they have not offered enough sacrifices yet, they have achieved the proper state, and Kureto's subordinates claim they are successfully controlling a seraph of the end. He orders Aoi to feed the rest of the sacrifices to the demon Abaddon to stabilize it. The demon's power rushes out and consumes nearby vampire and human soldiers while they look up in horror.
Mika carries Yu in his arms, and Krul is waiting for them. Although Yu is hurt, she says he will heal once he drinks her blood. She holds a hand out to Mika and says it is time they left. Mika glances back at the struggling Shinoa Squad and Narumi.
Yu tells Mika that Guren was crying. He says they have to save him. Mika insists he is Yu's only family. When Yu begins to disagree again, he appears face to face with Asuramaru within his mind. The trumpet from before rests between them. Asuramaru scolds Yu for being so greedy and says he does not have enough power to give them. He calls Yu a traitor and says Yu is betraying him by taking up that trumpet. He says that is the worst decision he could make and says that will erase what is left of Yu's humanity.
Yu answers that he does not really care as long as he can protect his family. He blows into the trumpet and is consumed by a massive power that splits the clouds.
List of characters in order of appearance: