Bellatrix was an evil bitch, no doubt. But at least she didn't hide her dark soul. Umbridge was kind of a latent sadist. I would not kill her though. Just put that bitch in Azkaban. I'm not a killer.

Umbridge

I would kill Bellatrix and send umbridge to azkaban because Umbridge is the least capable of escaping

Umbridge

I would kill Umbridge (for some reason I really like bellatrix's craziness)

Umbridge definitly

Umbrige BELLATRIX IS THE BEST

Umbridge ! Bellatrix is my favorite Death eater !

Umbridge.. duh.. someone will probably kill bellatrix anyway.

Of coure both of them