Life Essence is the primary resource in blood magic. By using Thaumcraft a mage can create Acolytes to sacrifice blood for their nefarious work.
In the above image, you will see Flesh Golems from Thaumcraft. Flesh Golems coupled with Fezz's can withstand Blood Magics Ritual of Sacrifice. To acheive the perfect balance you will need two rituals active Ritual of Sacrifice and Ritual of Regeneration.
The green on the golems above are the effects of the Flesh Golems regeneration. The ritual takes one heart at a time but the passive regeneration along with the rituals regeneration heals the golem before the ritual of sacrifice can take another heart.
Currently i have 54 Runes of Sacrifice on my tier 5 altar. Every tick of the Ritual of Sacrifice i gain 1k life essence. This with seven Runes of Speed refills the life essence before an item can consume it. Therefore creating an endless loop of Life Essence.
To refill the Life Essence consumed by the rituals, i pump out the excess Life Essence into a Mekanism Dynamic Tank. From this tank i can fill another altar and place an Orb in it. Keep in mind that the orb will only fill to its cap. You cannot use a Master Orb on a tier one blood altar and reach 1 million Life Essence. However and apprentice orb in your second altar will keep your life essence from reaching zero.
Not to mention it makes you altar seem far more sinister as now you have acolytes to assist you in your rituals!