Imperator is a complete joke now. We were 5/10 and ready to spend 3 nights on him, we had never seen beyond p1 before BrF (only reached him 2 days before brf).
He died in 18 pulls. We oneshot chogall even with no shield for 2nd Enveloping Mist. We 2 tanked and 5 healed it.
In p2 you can take 7 stacks of branded. All the mechanics have gone from requiring near perfect execution to just doing them okay.
Enjoy the kill.