[pokecrisis234]

Got Volume EX.
In addition to the short stories that Entropy already translated, there are also other short stories like...

Spoiler for Unreleased short stories content:

Iris and Lisa patrolling the girls' dormitory at night, Iris and Ariella doing the same, Ariella having to clear up some of Tia's misunderstandings, Firill and Lisa at the roller coaster, Firill in Akihabara and the girls designing a game centered around Yuu.

Fafnir Zero is just Brynhildr Valkyries, the short prequel released with the BD boxes featuring Brynhildr Class before Yuu arrived.

And Merry Christmas is split into 2 parts, the first being more serious...

Spoiler for Merry Christmas Part 1:

Loki and Sleipnir arriving on Midgard a few days before the party to help Yuu and Jeanne stop a kidnapping attempt on Brynhildr Class by beings that are supposedly the remnants of an ancient civilization that is different and inferior to Atlantis. It is also revealed that there are 7 'Deadly Sinners', 7 cataclysmic beings in the universe. Angolmois was one of them, representing gluttony.

And Part 2 being more silly and romcom...

Spoiler for Merry Christmas Part 2:

Firill setting up some kind of weird wedding ceremony with her father's help, where the girls have to shoot down a drone with paintball guns, followed by Albert asking them a question, which they and Yuu must answer identically and at the same time for their wedding to be recognized. Unsurprisingly, no one wins.

Finally, the artist is releasing an artbook for the series on the 2nd of July.
I think that's about it.