Vampiric Aura Question (in General)

I've noticed that my VA is real flaky. Sometimes it works every hit sometimes it doesn't pop off.

Does anybody know any details as to why this may be.
Also, before it is suggested, my VA is trained to a level that is very close to my MPB.

I'm just getting really frustrated with VA in general and wondering if ablative shield would be the better route for me, because of VA's inconsistencies.

VA works in a way close to that of GA. If the minion you hit had no life before you hit it, there will be no life to draw from.

Your opponent's DM can cancel your VA - it will tell you if that happens during the casting of enchantments. Also, VA does not work in ranged rounds.

Most people near the top unlearned VA a long time ago. Far too many people with DM up here. That's why Morgs and BoThs are so popular.

I realize about DM. My question is more focused to the fact that it doesn't work after every hit when DM isn't in play. For example I generally do multiple hits in a round. Sometimes I will get the VA every time other times it will be once during the round. That is my question. I know it doesn't work in ranged also. I apologize and should have clarified a little better.

If you're hitting 2 or more times in a round and you only get VA to work on the first hit, it's because that first hit killed your opponent and there's no more HP to leech.

A la "beating a dead horse"