Chapter 42 of "Owari No Seraph" is already available for online reading on Imgur. The latest chapter slightly deviates from the current story as it expands and involves more people.
But before any spoilers and predictions, here's a brief recap of the latest events in the chapter.
Lord Gilles, the 2nd Progenitor who rules Russia was visited by Lest Karr of Germany to talk about the current situation in Japan. The two leaders were called to convene due to a request from Japan with regards to their current situation.
As they convene, they were shown an image of Krul being tied to a chair and unconscious. Ferid informs them that Krul has been working with humans where they have successfully harnessed the power of Seraph of the End. As they speak, Guren and Kureto attack the city with full power that it started destroying Sanguinem.
Ferid also informs the council that they are currently overwhelmed by the human forces because of their power and needs immediate assistance. However, Ferid requests that they should leave Japan temporarily so he could personally deliver Krul to the council.
The chapter ends with Yuu, still tied up angrily shouting to let him go while threatening to kill everyone while Mika looks on pleading.
Finally, we are getting a bigger picture of what happens in the world of "Owari No Seraph." With the events in Japan potentially affecting other countries, more characters are thrown into the mix. Lord Gilles and Lest Karr would be featured more in the future chapters.
The Reddit forum on the latest chapter provides a good discussion of the council's ranking as well as the possibility of Yuu's demon developing and finally getting free.
The forum at Manga Helpers also highlights the upcoming attacks on Sanguinem. If Guren and Kureto's forces is successful with the attack, the council will have their hands full just to regain control of the country.