Guild Wars 2

On some burst skills like Gunflame it even decreases your dmg!!
(not only the tooltip dmg decreases but the actual dmg also)

Test it yourself and hit the same golem over and over with and without burst mastery.
Overall dmg with Burst mastery is lower then without burst mastery.
Thanx for the debuff trait! :-P

Post it in the bugs section. If you have time on your hands, I suggest making a video and putting it on reddit.

ANet will probably respond there.