shouldnt feeding them make them stronger since they are gaining energy from the blood which they drink ???

i dont even understand the ruins they reside in full of cattle and body parts but if it makes them weaker why are they eating it

it would be like super man eating kryptonite ? i dont get it

I don't know, I think it's something about stunting the effect of Vampirism so it doesn't ravage the body and the mind.

You have to risk going feral to have great power. I like the idea, but it doesn't really work for me in Skyrim. :\

I like to imagine they lose control of themselves if they don't feed. If they feed, they retain more control and don't become "feral".

They become farther and farther lost in being a daedric abomination the longer they go without blood. Blood is generally considered to be symbolic of life, and vampires are undead. Blood brings them closer to being the man (or mer) they once were, but deprives them of the power of a more feral vampire. The upside of drinking blood, then, is that it's far less obvious that they're a vampire, so they can walk among normal people without drawing attention.

So it looks like 'feral' is the answer then.

but i wish was that monsters drink blood to be stronger and you would get weaker if you didnt drink blood