Both Yu and Kimizuki succeed, but Yoichi becomes possessed and turns into a man-eating demon. As Yoichi attempts to kill his friends, Guren orders Yu and Kimizuki to kill Yoichi. They scuffle with their new weapons, but eventually Guren is able to snap Yoichi out of the thrall consuming him.
Yoichi regains control over the demon, and everyone is relieved. Guren tells them that they will now advance to the front lines.
Meanwhile, the vampires are heading to Tokyo and Mika says that Shinjuku will be first.
An 8-year-old Yoichi Saotome stands with his elder sister as the vampires, Lacus Welt and René Simm, enter their home. She sends Yoichi under the bed and orders him to stay there no matter what. Lacus enters the room, and Yoichi sees his sister's feet dangle in the air as she whimpers and blood spills on the ground. René enters the room and tells Lacus that they have been summoned to the headquarters. Lacus drops the corpse of Yoichi's sister, and she falls right in front of his face. Yoichi covers his mouth to keep himself from making a sound as they leave.
Yoichi looks out at the corpse of his sister and whispers to her. She suddenly opens her eyes. She informs Yoichi that she is replaying his deepest memory. When Yoichi asks if his sister is alive, she grabs him by the collar and lifts him from the ground and quickly informs him that his sister is dead.
A pre-adolescent Shiho Kimizuki watches over his sleeping sister in a ruined apartment.
When his sister, Mirai, wakes up, she begins to tell him he can always leave her if she is holding him back. He interrupts her and says that, if they die, they die together. As Kimizuki goes to get food for her, she begins crying and says how he cries nightly about how hard life is and how much he wants to leave her behind. He asks why she would say such a thing. Mirai sits up and states it is because he is a selfish human who thinks only of himself. Kimizuki realizes that she is the demon who goes on to state this is not a hallucination but rather the memories and truth inside himself.
In the ceremony room, the twin blades in Kimizuki's hands begin to tremble. Guren comments that he looks like he will get through it, and he looks at the other two boys.
Yūichirō Hyakuya walks through a space filled only with clouds until he hears 12-year-old Mikaela Hyakuya call his name. He turns to see Mika with a teddy bear in the orphanage they were at briefly when they were both 8 years old. Yu demands the demon stop imitating his family. Mika comments that he thought he was touching on his softest part but wonders why Yu was not rattled at all. Yu orders him to give up and give him power. Black smoke is emitted out of Mika before he collapses to the ground. Yu cries out his name and runs forward, only to be stabbed with black tendrils formed by the demon. The demon rises as a black formless mass. He realizes that Yu fought a low-rank Myo-o demon before. The demon asks why he wants power so much. Yu answers it is for revenge and because he lost his family. In response the demon claims that he can give him endless power for revenge.
Akane's voice says that it is not enough, and Yu turns his head to see the corpses of the rest of his orphanage family lying on the ground behind him. Akane speaks how she cannot give Yu power unless he dedicates himself to revenge. Mika, Akane, and the other children ask Yu if he would abandon them again. They tell him to get rid of love, that demons hate love and only need lust. They question him if he is going to be the only one to make friends and live happily ever after. They say that Yu being the only one to survive is not fair. Yu answers that he has not forgotten about them, so Mika instructs him to get rid of his friends and that they are his only family. As they continue to raise the topic of revenge, Yu screams at the demon to stop. He demands power in order to protect everything.
Yu and the smog-like demon appear in the landscape of clouds again. The demon comments on Yu's incredible contradiction of love and lust and states that this is the reason why humans destroy the world. He concedes to follow Yu as long as his heart is strong, but he will take over the moment any weakness is sensed.
Informing him that his name is Asuramaru he reveals that Yu is about 10% no longer human. He suspects human experimentation and warns Yu to not trust humans, which are more terrifying than demons or vampires. When Yu requests more information, Asuramaru declares that their contract is complete.
Yu awakens, and Guren asks him how it went. Holding a sword with a green blade, he replies that it went great. Kimizuki chimes in and states that he took too long. They look at Yoichi, who is still confronting his demon.
The demon in the form of Yoichi's sister clicks a desk lamp on and off while resting her jaw against her hand. The 16-year-old Yoichi asks her who she is. She reminds him that he asked for her power. Yoichi recalls that he was in the middle of the contract ceremony and tells the demon that is a mean form to take. She tells him bluntly mentions that he has an awfully stupid-looking face
where all she feels is stability, gentleness, and a love for others inside of him, not vengeance. The demon says she hates those things. Yoichi affirms he wants revenge, but the demon tells him that he was glad he was saved and does not want to kill anyone, further that Yoichi hates conflict. The demon is not going to put up with such nonsense as vengeance that cannot kill and adds she hates people with such weak wills.
Black smoke appears around the demon, who states she will earn Yoichi's revenge for him instead. Piercing his hand through Yoichi's chest the demon claims he does not have the will to fight back and certainly is not worthy of being her master. Yoichi looks into the face of his sister as he loses control.
In the ceremony room, a large crack divides the large ogre-like head overlooking Yoichi. His body leaps on top of one of the heads, and Guren comments that Yoichi did not make it. He says two out of three passing the test is not bad. Yoichi has sharp fingernails, pointed teeth, two small horns, markings under his eyes, and slit pupils. He complains about humans being a pain and manifests a large green bow.
Guren announces that Yoichi has became a man-eating demon and orders Yu and Kimizuki to kill it. The man-eating demon attacks the humans, and Yoichi and Kimizuki draw their weapons. Yu disagrees with the orders, but Guren says that Yoichi will not come back. Yu knocks the bow from Yoichi's hands, but Guren reminds Yu that the demon is in Yoichi, not the weapon. He and Kimizuki continue to struggle. Shinoa asks Guren to rescind his order, and he tells her to do it instead if she cares so much.
Although Yu's attempts to snap Yoichi free of the demon's thrall have been in vain, he continues to try and talk Yoichi out of it and throws his sword aside. Alarmed, both Kimizuki and Shinoa step in. Guren asks if Yoichi is just going to stay under the bed again or if he is going to come out and protect his comrades.
Yoichi relives the scene as his sister orders him to stay under the bed, but he says he does not want to stay there anymore. He wants the power to protect his friends and destroy all of his enemies. The 12-year-old Yoichi becomes the 16-year-old Yoichi as he demands power.
The demon loses control, and the arrow misses Yu. Crying, Yoichi throws the bow aside and runs to Yu and hugs him.
Guren tells him he took too long to come back and kicks Yu in the abdomen, knocking him out. Yu wonders why he was kicked instead of Yoichi, and Yoichi fusses over him. Guren speaks how Yoichi has talent, but guilt has been draining his will to live. He tells Yoichi to not worry about revenge and live to protect his friends now. Guren wakes Yu up and directs him to forget about his old family, that there is nothing there for him. Guren asserts that this is Yu's new family now. Since the three boys managed to acquire their cursed gears and work somewhat as a team, Guren says he will send them out to the front line.
He says the Kansai vampires are planning to retake Shinjuku.
On a plane, a vampire announces that they will soon be arriving in Tokyo. She tells the numerous vampires inside that the Japanese Imperial Demon Army is expected to attack at Ikebukuro, Shinjuku, and Shibuya. Lacus asks Mika if he heard that, and Mika says Shinjuku will be first.
Differences with the manga
|Yuichiro's battle against Asuramaru is first. Shiho Kimizuki's first battle against Kiseki-o is not shown. Yoichi's battle against Gekkouin is not revealed until after he is possessed. Shiho Kimizuki and Kiseki-o's mental warfare is not revealed until chapter 21 in the manga.||The battles against the demons are shown in the order of Yoichi, Shiho Kimizuki, Yuichiro, and then Yoichi again.|
|Lacus and René enter the bedroom together.||Lacus enters first.|
|The vampires have more details in their boots, and they have a black and white design.||The vampires boots are all black without details.|
|Yoichi converses with Gekkouin in a white and empty space and only enters the bedroom while relieving that memory in an endless loop.||Yoichi and Gekkouin stay in the bedroom.|
|The scene with Shiho and Mirai Kimizuki happens during the day. The manga shows more of their interaction and the other humans they are with.||The scene occurs at night and only shows the two siblings.|
|The contract ceremony is in a smaller room with full-bodied statues looking over magical circles.||The contract ceremony is in a larger room with stairs leading up to the ceremony circles. The full-bodied statues have been replaced with massive heads.|
|Yu immediately steps into a white plain surrounded by the shredded corpses of his Hyakuya family members.||Yu walks into clouds until he sees Mika, and the scene changes to the orphanage.|
|The smoke is more massive when it flows out of Mika's mouth.||The smoke encircles Mika.|
|Yu gets stabbed with one large attack through his chest and abdomen.||Yu gets stabbed in numerous places.|
|A white light flashes from Yu as he has the will to fight against Asuramaru.||There is no such light, but the scene switches back to the clouds.|
|The man-eating demon fires numerous arrows at once.||The man-eating demon fires only one arrow at a time.|
|The man-eating demon attacks Shinoa, Yu, and Kimizuki first. He attacks Guren afterward.||The man-eating demon's attack is deflected by Guren first.|
|Guren does not bring it up after stating he will send the three boys to the front lines.||Guren reveals that the Kansai vampires are planning to retake Shinjuku.|
List of characters in order of appearance:
Anime images provide a visual overview of the events of Episode 6 with depictions of the characters, Seraph of the End world, scenarios, artistic style among other areas.
|Episode 1 • Episode 2 • Episode 3 • Episode 4 • Episode 5 • Episode 6 • Episode 7 • Episode 8 • Episode 9 • Episode 10 • Episode 11 • Episode 12 • Episode 12.5 • Episode 13 • Episode 14 • Episode 15 • Episode 16 • Episode 17 • Episode 18 • Episode 19 • Episode 20 • Episode 21 • Episode 22 • Episode 23 • Episode 24|