How it works is that as you attack the target you gain up to five stacks of a buff called Blood Reserve, which combined can heal you for up to 2,200.  That doesn’t sound like a whole lot but then again the amount healed isn’t really the best part of the enchant.  The best part is that the enchant fires off automatically when you are reduced to under 35% of your total health pool.  That means that it works much like the old Commendation of Kael’thas but instead of giving you dodge raiting it fires off a little extra heal for you.  Does the 2,200 number not excite you?  Well let’s look at some numbers:

• Runic Healing Potion: 2,700 to 4,500 health.
• Super Healing Potion: 1,500 to 2,500 health.

The effect of a full five stack of Blood Reserve going off and healing you is equivalent to drinking a nearly maximized Super Healing Potion!  “That’s not amazing, it’s just a Super Healing Potion,” I hear some of you saying and while it’s true you might be forgetting two things:

1. It’s automatic. You never have to think about using it, it just fires off the instant you fall below 35% health.
2. Potion Sickness. The days of being able to chain-chug pots as an oh-shit button are gone.  We know this and we aren’t happy about it but we’ve adapted.  I just recently looked at a WWS report from our Auriaya kill this week and I noticed that a healthstone I used gave me 4,337 health but, again, I could only use it once and I had to trigger it.  I regained a total of 8,828 health from Blood Draining over the course of the same fight, that’s the same amount of healing as if I had used an additional two healthstones!

Bear in mind, however, that while Blood Draining is fantastic for progression fights where your raid might be a little under geared or new to the content that you’re attempting, it will be very much wasted if you are doing farm content since it will rarely, if ever, proc.  If you are looking at farm content, look at other enchants.