Is Vasharti's reflect skill bugged?

Is vasharti's reflect skill bugged? Cuz it's only supposed to do 2250 points of damage. But how does it 1-hit people instantly? And does his casting speed increase through out the whole duration of the fight? just some curious questions

 

im not sure but i think that he kill u in 1 hit if for example he is using the red flame shield and u atack he using the blue flame buff

 

Vasharti has two reflective shields, Blue and Red if you attack him with either of these shields up you take 2200 or so per hit reflected. Now to counter that reflect the flames in the room give a buff blue with blue and red with red. If you attack with the same color buff on you will not take reflect damage. Since he changes his shield though if you attack and have the opposite color buff on it will result in an instant death. You should check your game options and have show enemy cast (or something like that ) checked off in the first page at the bottom of you options. So you can see when Vasharti changes his shield.