Sanguimancy, or hemomancy to some, is a highly contested magic that is often seen as a dark art. However, blood magic is no more dark magic than any other magic; indeed, that could not be further from the truth. Blood magic is one of the purest forms of magic that one can achieve, as it is the oldest magic to exist since time immemorial, before the void that existed before the universe. However, it also costs more than many would be willing to pay, as the more taxing a spell is, the more likely it is that you will die from blood loss and your life force being drained as it is used as fuel for arcane reality manipulation.
To learn more spells, the practitioner must perform a spell to reach through time, reach the void, and look into it as the very nature of the universe is revealed to them. Oftentimes leaving the recipient blind for the next few minutes due to the overstimulation of looking so far into the past and learning things that mortal minds should not have understood.
If one thing is to be certain, the scholars of old have learned that nothing is ever free, and everything comes at a cost; the only question is if you are willing to pay the price.
(This power essentially allows you to do anything with enough research and preparation.)