Revenge.

Revenge comes at a price. The question is it really worth it in the end? Agamenmon kills Clymnestra daughter and in revenge Clymnestra  kills Agamenmon . Orestes kills Clymnestra because of everything  else. So in the end everyone pretty much dies due to revenge. If Agamenmon cared more about his family than the war then he would not have killed his daughter, and his family would still be alive. but if the other two had not let revenge take them over, then it would not have ended badly for them. Clymnestra would still be alive and Orestes would still have is family. So In the end, is it worth it? The answer to that is no.

PS I commented on michelle nellsch's a bloody cycle of revenge