User blog comment:SpookyBoogie27/Light Novel Spoilers/@comment-82.178.42.183-20140208044915/@comment-1359322-20140208111828

Yes, they were killed by the Gremory Team and Freed.

The 2 Rooks were killed by Xenovia.

"So this is the attack power of Xenovia without any restrictions! And all of that was the holy power! If the opponents are devils, then it would be a deadly attack! No, it’s not something so nice like that! They will disappear without a trace! The two Rooks did perish!"

The eight Pawns were killed like trash.

"I, Koneko-chan, Xenovia, and Gasper defeated 8 Pawns and 2 Rooks easily. I thought we were at disadvantage before the battle, but when we battled them we got the complete victory."

The two knights were killed by Freed.

"“Hmm, are you perhaps looking for the two Knights?”

His words as if he read my mind once again. His sickening smile sure does disturb me….. Freed chews with his mouth, and spits something out. When I look……it is a finger!

“I ate them.”"

"The Queen and the two Bishops are on the ground while smoke is coming from their bodies. ……..No matter how you look at it…….they won’t be able to fight anymore…… And this is the result for interfering in their argument……. It would be weird if it’s coming from me, but it was a horrible match. More like it is scary to make the two Onee-sama angry. And their quarrels haven’t ended!"

They probably survived but i don't know, maybe they are also dead with that attack by both Rias and Akeno.