Seraph of the End 4: Guren Ichinose: Catastrophe at Sixteen

Seraph of the End: Guren Ichinose: Catastrophe at Sixteen (Book 4) is the fourth book of the Seraph of the End: Guren Ichinose: Catastrophe at Sixteen light novel series, which includes Guren's past with Mahiru and his encounter with many characters of the manga sequel, Seraph of the End: Vampire Reign.

It is the second half of the second English omnibus.

Prologue: The Demon's Curse
Guren knows his desires and surrenders his humanity, turning his world pitch black.

Chapter 1: Night of Desire
Guren meets the demon Noya in a blank white space. He approaches Guren, tainting the white world of his mind black. He gives up his humanity. When he comes to, he feels different and notices he no longer cares about human dying or suffering and only has an immeasurable desire to kill.

Chapter 2: Shibuya Is Burning
The war between the Thousand Nights and Imperial Demons begins. Mito is captured and Norito is nearly killed. Saito orders soldiers to rape Sayuri and Shigure. However, Guren invades the school and begins slaughtering all of the Thousand Nights soldiers he comes across but nearly kills his friends as Noya takes control. He tries to have sex with Mito, but Goshi saves her. Shinya seals Guren within the school, and Guren gives into the curse.

Chapter 3: Still Hiragi
Sakae Ichinose surrenders information to the Imperial Demons, and Shinya and Kureto plan to rescue Guren. Mitsuki Iori is taken as an experimental subject for the demon’s curse.

Chapter 4: A Friend in Need
Guren returns to his senses inside the school building. Shinya, Norito, Mito, and thirty troops wielding brand new mass-produced cursed gear appear and chain the demon down with curses, giving Guren the ability to maintain his sanity while severely restricting the demon's power. Kureto reveals that the Thousand Nights and Imperial Demons have now joined forces. He holds Guren’s father and all of his followers hostage while experimenting on Shigure and Sayuri. He commands Guren once again to kill Mahiru.

Epilogue: The Seraph of the End
It is September 2nd, 2012. The team plays Bomberman at Guren’s place until Mahiru shows up and Guren attempts a double-suicide by jumping off at 25-story building with her. She saves him before he reaches the ground and quickly heals her own broken bones after the landing. Although they believe ten soldiers with cursed gear should be enough to kill her, she easily slaughters twenty of them without a scratch and disappears.

She leaves him a package describing the Seraph of the End experimentation being performed by the Thousand Nights along with a list of seraph test subjects, including Yuichiro Amane, Mikaela Shindo, Shiho Kimizuki, Mirai Kimizuki, Yoichi Saotome, and Tomoe Saotome.

Characters
List of characters in order of appearance: