Ruined might be too dramatic a word here; perhaps "undermined" would work better.
Anyway, my pick is the titular Darkness from The Darkness 2
An ancient, primal power from before the time of creation itself that constantly tries to tempt its host into violence and evil? Sounds interesting to me, can't wait! . . . except for the fact that its voice is ridiculous. It just sounds so feral and silly. A 12 year old trying to sound evil would produce a similar voice. I would have preferred a smooth, suave voice. After all, one of the main plot elements is that it constantly tries to seduce the protagonist into giving in to its will.
Anyway, my pick is the titular Darkness from The Darkness 2
An ancient, primal power from before the time of creation itself that constantly tries to tempt its host into violence and evil? Sounds interesting to me, can't wait! . . . except for the fact that its voice is ridiculous. It just sounds so feral and silly. A 12 year old trying to sound evil would produce a similar voice. I would have preferred a smooth, suave voice. After all, one of the main plot elements is that it constantly tries to seduce the protagonist into giving in to its will.