Possible bug with lifedrain attacks? - developers please read

Originally posted by Norfleet:
Zen says that the fatigue is inflicted regardless of whether the attack penetrates protection: It's possible that the attack "hits", but doesn't inflict any damage through protection, but the fatigue is caused anyway. Since no physical damage is caused, mirror image doesn't fail.

This is also true of anything that has a secondary effect but doesn't deal any actual damage. Though it may or may not be on the same level as Life Drain. Meaning, a weapon that has a secondary effect of poisoning, that doesn't actually hit through protection can still poison if the unit is not immune to poison. Same with things that have effects like "Tangle Vine". Some effects (Can't remember off the top of my head) require damage before they are applied AFAIK but Life Drain and numerous weapons with secondary effects do not.