Upon my honour I do swear undying loyalty to the Emperor, Titus Mede II, and unwavering obedience to the officers of his great Empire. May those above judge me, and those below take me, if I fail in my duty. Long live the Emperor! Long live the Empire!
I did a playthrough as the dark brotherhood to kill the emperor before joining the legion so I could kill Ulfrick next.
On my last playthrough I destroyed the Dark Brotherhood
I usually do that now. It destroys alot of game content, but killing Astrid when you first meet her makes sense if you want to play a character with a conscience.