Bypassing Defenses?

[Haldir]

I am curious if there is a way to bypass immunities. I am specifically interested in ways to ensure death effects/negative levels will be applied to a target. I have an interesting idea for a build, but I'd hate to be shut down by a 4th level deathward.

Ways to dispel that specific spell of my choice on a target would function just as well, if any such exist.