Owari no Seraph: Ichinose Guren, 16-sai no Catastrophe - Vol. 4 Ch. 13

[MangaDex]

 

[Yakuza_Luxiphan]

It looks like Guren needs to teach these scientists a lesson: "Do not play with fire."

 

[MhaiWind]

It's interesting to see the lore expanded from the Light Novels. I don't recall this part while reading it.

In some of the later chapters you actually see one of the demons that Mahiru deals with, and it was a great reveal of something never directly stated in the LN source.