A couple of reasons why you got killed by one and are now coming to the forums to complain about them:
1. You are bad at the game and don't want to form a way to counter them.
2. The warlock who killed you plays their class very well.
3. Coming to the forums to cry for nerfs just proves that you are bad.
-
I hate everything about stormcaller warlocks but the only thing that I think that could really be classified as overpowered is their melee. You should not have a melee with more range than a shotgun that also has auto aim. I really don't see how that melee made it into the game.