Trumpet of the Apocalypse

-- is the fortieth chapter of the manga series, Seraph of the End: Vampire Reign.

Spoiler Summary
Mika and Yu joins the battle after Yu saves Shinoa from Kureto's attack. They make their plan to escape the battle with the help of Mika and Makoto Narumi. Together, they prepare themselves to initiate their plan.

They once more engage in combat with Aoi's chains, soon afterwards being interrupted by the appearance of the vampires led by Krul Tepes. Kureto commands the entire remainder of the Japanese Imperial Demon Army to engage combat with them to buy time until the "experiement" was completed.

Shinya and Mito Jūjō joins the fray as well, fending off attacks from Yu and the others and tells them to escape. They are forced to a standstill by Guren confronting them in their paths. Mika defends Yu as Guren attacks him and comments once more that humans couldn't be trusted. Kureto shouts at Guren that the experiment is starting.

Without fail, Guren expertly slays both vampires and humans to sacrifice more for the experiment.

Kureto shouts at soldiers to control the power and do not let the angel out of control. However they are stopped shortly with the sudden appearance of Mirai Kimizuki, now a four-winged Seraph as a result from the earlier experimentation carried out by Kureto's orders.

She is once more restrained by Aoi's chains as everyone moves to attack. Yu confronts Guren about his motives, the latter soon crying and tells him to run before he suddenly attacks Yu and leaves him fatally(?) wounded.

The "experiment" on the other hand grows in power, Kureto and the others turning their attention to. Mika takes the chance and escapes with Yu, soon meeting with Krul. She tells him to depart with her. Yuu on the other hand begs Mika to help Guren, though the other is stubborn to do so.

In his mind, Yu speaks to Asuramaru. The demon tells Yu that he is too greedy and that now he will betray him by accepting the trumpet and that his humanity would vanish. Yu disses the risk, stating that he is willing to do anything to protect his family.

Blowing on the trumpet, he in real life soon erupts with sudden, spontaneous power. Ultimately, the Seraph of the End experiement becomes completed(?).

Wow