Kimizuki takes the drug, and the humans get into position for battle. Kimizuki and Guren talk about why they are doing what they're doing.
As Yu demands even more power from Asuramaru to fight against the sixth trumpet, Shikama Dōji starts opening the doors restricting the emotions in Shinoa's heart.
List of characters in order of appearance:
- Shihō Kimizuki
- Ferid Bathory
- Mirai Kimizuki (Mentioned only)
- Shinoa Hīragi
- Mitsuba Sangū
- Mito Jūjō
- Makoto Narumi
- Yoichi Saotome
- Shinya Hīragi
- Guren Ichinose
- Norito Goshi
- Shigure Yukimi
- Yūichirō Hyakuya
- Sixth Trumpet
- Mikaela Hyakuya
- Shikama Dōji
- Mahiru Hīragi (Mentioned only)
Kimizuki orders Guren to give him some of the drug being used on Yu. Ferid hands it to him, telling him that he is joining them as a co-conspirator in their taboo experiment. Ferid says that Kimizuki will sacrifice anything to save his sister, including his friends, and Kimizuki agrees. Ferid says that it's precious and compliments Kimizuki on being so vivacious and alive. Kimizuki tells him he hopes Ferid keels over and dies.
The human soldiers get into position for battle.
When Kimizuki asks if Guren is going to lecture Kimizuki on the fact he's now doing the same thing as Guren, he replies he will if Kimizuki wants him to. He asks why they have to keep doing this over and over again. Guren answers that it is because they are alive. He says that if Kimizuki dies, then his sister dies with him. Therefore, they must live. They are all living for their families, even if that requires doing something unforgivable or forbidden. Kimizuki says he almost trusts Guren a little after he said that.
Both of Yu's sclera are black, and his hands are turning into claws. He appears to have three or four wings instead of the usual two as he fights against the Sixth trumpet.
While watching Yu battle, Shinoa wonders how Yu can become so worked up about other people or how he can become attached to another so easily. Meanwhile, Yu demands even more power from his demon. Shinoa resents the fact she has no raging passions or welling emotions.
Shikama Dōji interrupts her thoughts where he supposes that she has desires, such as lust. He says that Shinoa is at the age where she wants to experience love. He points out that Mahiru had sex with Guren when she was sixteen and mentions how passionate she was in both life and death. Shinoa says she doesn't compare herself to her sister. Shikama Dōji tells her she is much stronger than Mahiru ever was.
A closed door lies at Shinoa's feet in her mindscape. Shikama Dōji asks her if it's about time she opened that door. He mentions that Shinoa can build thick walls in her heart to keep love, lust, joy, sadness, and her other emotions at bay. Shinoa states that those walls keep Shikama Dōji from invading her heart. When Shikama Dōji asks her what a human has without passion, Shinoa answers, "Peace." Shikama Dōji tells her she is lying and wants to experience love. He says that her heart races when she watches Yūichirō Hyakuya.
Then, Shikama Dōji starts opening the door.
Manga panels provide a visual overview of the events of Chapter 66 with depictions of the characters, Seraph of the End world and scenarios.