It sounds as though your Master was extremely unworthy of the Servant he summoned.

[Diarmuid might not agree with all of Kayneth's choices when it comes to battle, but he is not going to call the man a coward. After all, he had come to the fight, even if he had stayed hidden within the shadows instead of standing at his Servant's side.]

You have my sympathy for your misfortune.

[And, since he can hear the irritation in the other man's voice, Diarmuid says nothing more on that topic. Instead, he shifts over to the reason Cu Chulainn has given for not wanting to fight.]

I guess I see it in a different light than you do. It is not so much about glory as it is completing a duty that has been handed to me. If winning this war is the only way for me to return to my current lord so that I can fulfill the vows I have made to him, then I will put my all into finishing this war.

I am just saddened I will not have the chance to fight it with you at my side. However, the choice is yours. Even heroes deserve their rest.