Although this seems to be posted by a young/uninformed/bad player,
Ill try to reply as serious as I can.

You are complaining about the dk class their selfhealing..

-frost and UH, overall bad selfhealing but yes the conversion talent is too strong in a 1V1 situation,
but who cares about 1V1 .. its not a problem in 2s , 3s , 5s

-blood yes stupid selfhealing and immortal vs any melee dps
Im quite frustrated that blood dks are back to the same silly state when they introduced vengeance in pvp.
(yes I know there is no more actual vengeance in pvp, but they increased their dmg alot in the last months)
Atm they cannot be killed by any melee dps but they can however put out more then decent dmg.
So if you are playing some 2s as melee dps, then just hope you dont meet a troll that is playing blood...

So if there is any reason to complain than it should be about blood dks, they are utterly stupid to face
as a melee dps, this is such a bad design, but you only find them in 2s and bgs so...