If a 10 HD target has taken 3 negative energy levels, is it now considered to have 7 HD? I'm asking because of spells like Cloudkill, Eyebite, and Circle of Death that only effect (or have different effects) creatures under a certain number of HD.
"The creature is also treated as one level lower for the purpose of level-dependent variables (such as spellcasting) for each negative level possessed."