Board Thread:Lore Discussion/@comment-6716700-20130319133042/@comment-7153552-20130401233251

Epzo wrote: The question isn't what YOU would do but what the Dark Brotherhood would do, based on what we know about them.

I can't find fault with anything Epzo has said here. He's right, the question at hand isn't about you as a person. It's not even about you as a character. It's about you as the Listener to the Night Mother of the Dark Brotherhood. Their lore tells us that while they exact revenge for other people, they do not practice it for themselves. It serves no purpose or ultimate gain. There has to be a contract brought to the Night Mother through the ritual, that I assume Sithis hears and and tells the Night Mother about or something to that effect. Life on Nirn isn't simple, much like life on Earth. However, for the Dark Brotherhood life is very simple; follow Sithis and the Night Mother, complete contracts, kill people, emjoy it, come home to rest, dream of doing it all again, rinse and repeat.

In short, no. The Brotherhood has no real reason for vengence. They would fight back if attacked, but self defense is not revenge. They need secrecy to survive more than anything, and starting a mini-war is not secretive.