Owari no Seraph: Ichinose Guren, 16-sai no Catastrophe
Ongoing | Kagami Takaya,Asami You | 2000 released
As someone who read the light novels, the first chapter is a filler that only confuses, doesn't add anything relevant to the story. I would recommend starting reading on chapter 2 as that's how it originally starts in the book, and so far such a perfect adaption and eye candy drawings.
Kamisama Hajimemashita