Ya its not exactly red buff, red buff is 30 percent, but because of WoD perks its 50 percent. So technically its the WoD perk that is the culprit but no buff, green, buff, yellow buff you do next to no damage. Only time you see good numbers is from red buff because its 50 percent. If it was 30 percent it might not even be playable, Killing spree would do about as much damage maybe less than dance.
Just make the rogue cc-able during Killing Spree, and maybe nerf the damage some
and put it elsewhere, like Evis.
If you are doing burst, you need to be able to have cc affect you. That simple. No excuses, no exceptions. That adds strategy to the game. When you let a player burst someone without being able to be controlled, it just destroys the skill required to play.
While they make this change, they need to do the same thing to every other burst CD that let's this fly, like Ret wings 4 piece. I have no hate against the spec, but the same rules need to apply.