When Ulduar was released, two new ‘tank’ enchants were released with it. These were Blade Warding and Blood Draining. Both are drops from various 25 man bosses in Ulduar.
While both enchants are still very new, the intial feedback from the community has been that these enchants are rather lackluster. The Developers wanted to avoid having an enchant every tank felt they must have like 50 stamina, so we get two very expensive enchants that don’t give you the bang for your buck.
Blood Draining - Permanently enchants your weapon to sometimes grant Blood Reserve when striking an enemy or inflicting damage with bleed attacks. When you fall below 35% health, Blood Reserve restores 360 to 440 health. Lasts 20 sec and stacks up to 5 times.
Blood Draining will work out to about a 2k heal when you health drops below 35%.
This has long been thought to be a poor enchant for Tankadins because of the negative synergy with Ardent Defender. The fear was that the enchant would proc and take you just out of Ardent Defender range. This would cause Ardent Defender to not mitigate the next hit, so the Enchant ends up killing you in a way. But no one had the hard numbers.
Enter Theck of Blackrock. In addition to being a Tankadin, Theck is a level 80 Mathematician (Elite). He did some very nice simulations of the effect of the enchant and how it interacts with Ardent Defender. The entire discussion, along with the graphs is in this thread on Maintankadin.
Let me give you the highlights.
- “While Blood Draining can push us out of AD range, and thus cause "leapfrogging" that kills us, reducing our Time To Live in some situations, it also adds Time To Live to other situations where we were in AD range but had slightly less HP than the size of the incoming hits after AD mitigation is factored in.
- As a result, at least in this simple analysis, Blood Draining will never reduce your average TTL, assuming that your "starting health" obeys a flat probability density function. So at least in that respect, the naysayers were wrong.
- Yes, the above is an unreliable (and probably incorrect) assumption, but without a more involved model of how healing effects change the probability density function, it will be hard to come up with anything rigorous. Empirical data might help here.
Then he proceeds to added healing to the simuation.
- Adding healing to the equation extends the range in which Blood Draining is useful.
- A good rule of thumb is (AD_Threshold + Incoming_Heals - Boss_Hit_size) > 0. The bigger the value, the better the enchant is.
- Blood Draining never reduces your TTL. The extra AD Leapfrogs it causes will always be at least offset by the extra AD saves it causes.
It means BD is better than most people assumed. It's very easy to imagine one bad scenario and draw a conclusion from it that's incorrect because you failed to notice a compensating good scenario