For some of us the fight was bugged. As I said previously, I was unable to interrupt his attacks no matter what I used. Till I re-logged and fought him again, then I caved his head in in seconds. And I was a guardian built entirely for damage absorption, not dps.
So, yes, the fight is not that bad, but it does have bugs related to it that can make it a royal pain. Even with the bugs, he is much easier if you're built for dps, as you can just down him before he gets a chance to do any real damage.
If your interrupts don't work, try quitting out of the game, then logging back in. That's what fixed it for me. Then have your interrupts ready for when he hits 10-20% HP for his final blast you across the room move. If all else fails just bring in a dps buddy and blast him. He does die really fast if you have decent dps. I actually didn't use t7 during the fight where I won because he just pulled aggro and made me chase the Emperor around, and slowed my damage output.