User blog comment:B214/Volume 17 spoilers./@comment-24.2.168.254-20140220012350/@comment-16281343-20140220012908

Well, Euclid is blinded by his sis-con actions and Grendel just wants to fight. And Euclid was defeated by Issei using Longinus Smasher. So, I don't think Euclid was expecting to be defeated.

Althought their is a chance that some traitors will free Euclid and he will just act as a prisoner.