Qi Vampire
1) An individual whose presence in your life results in most of your interactions with them leaving you drained, spent, and feeling like your own Qi ("life force" energy in Traditional Chinese Medicine) has been sucked right out of you; 2) A two-legged spiritual and/or emotional parasite of epic proportions; 3) That friend who always has some sort of disaster going on in their life that they can't help but impose into YOUR life each time.
My friend's divorce was over five years ago, but every ongoing battle with his ex, over cash and kids, gets described to me in minute detail on a daily basis. The man is a Qi vampire!