A little over 700 years ago the 'Last Empire' as the people of today call it was destroyed by its own rulers. The most powerful wizards of the time were no longer content to rule de-facto, they wanted total control of the empire's resources for themselves - each of them for himself. The result was a subtle splintering into opposing groups, unseen battles through proxies, minions and within the paths of sorcery. One among them, a half-elf working alone whose name has been carefully removed from every single accounting, excelled in particular - the artifacts of sorcery he created, the spells he cast on the two occasions where he openly clashed with other contenders to the mantle of Sorcerer-King, are a thing of legend and dread even today.
When all but five mages had perished or enslaved, he suddenly changed, seeming no longer interested in fighting over the control of the empire. Instead he withdrew to his main stronghold and paid no heed to the structures of power crumbling around him. The greatest of his (former) rivals however found out where the half-elf's research had led him and to what extent his influence had grown. In utter terror he negotiated a temporary treaty with the three remaining mages and together the four began a ritual, that would destroy all items of magic, all ongoing spells, all sorcery bound into living and unliving creatures and everything else within the enemy's vicinity. It worked well, all too well. When all was done, not a single invested item of less than artifact status remained and not much else besides as the stored energy within them burst forth violently and destroyed the great cities of the empire along with almost all practinioners of magic.
The ritual was too late in stopping the unnamed wizard, though. At the moment of his grand spell's conclusion over a week past he had shed his body and had weaved his mind and soul into the very fabric of existance as a living spell several magnitudes beyond anything the world had seen before. But less than the quantity of power it was the quality of power, that made the difference. True Necromancy, a discipline last employed in the Grey Age of the elves, many millenia past, the blending of sorcery and the manipulation of cosmic energies known as 'psionics' by some, was the flavor of Vampyr's spell and explains, why this (most likely false) name was attributed to him: Not only had his power increased tenfold in his new form, he could *add* to it by consuming the life-forces of others (an utter impossibility by the laws of sorcery) and spawn others like himself, over which he had total control (another impossibility). Within a bubble of folded dimensions the ritual with the sole aim of destroying him didn't as much as reach him, although some of his newly created servants were extinguished in the most literal meaning of the word.
It is unlikely, that Vampyr or whatever he (it?) calls himself remains on this world. Most likely he has followed the elves through the Paths in the Sky, leaving for worlds unknown, a fact of which the gods are most grateful. Some of his 'children' remain, though they are few (one or two per continent at most) and don't create more of their kind, for even though they possess vast powers and can hide their nature from others, the same doesn't hold true for lesser 'vampires' - and detection would be most unpleasant.
The living spells that are vampires don't need to feed on the life-force of others and most don't. Their powers are far-reaching and as beings of necromancy many rules of conventional sorcery do not apply to them. For example they alone (or at least some of them) ave the power of true shape-shifting and unlike wizards they have power over the minds of others. Short of the highest orders of spells or the intervention of gods nothing can permanently destroy them, but the physical bodies most create for themselves can be destroyed normally and they can be weakened severely. Summarized these 'vampires' rival (and in some fields exceed) the power of the gods and you'd better be an ascendant yourself to take on one of them.
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In a different setting blood-magic is the prevalent type. Wizards use their own blood to power spells, which are often very nasty in intent and consequence for all involved. The level of power a magic-user can attain is dependant on his descendance - the power in inherent to his blood and can increase only so far. It is possible however to drain the blood from another and adds its power to one's own, but even among the most wicked of blood magi the mere mentioning of this practise is enough to invite fearful glances and violence.
Some blood magi manage to cheat death by animating themselves through the power of foreign blood. Even though they are usually of lesser ability (those with enough power simply don't die), their single-mindedness and ferocity (think drug-addict) coupled with their draining powers makes them quite dangerous. But in the end they are just pathetic side-notes, constantly on the run, constantly searching for powerful blood but avoiding those who control their own power, constantly longing for life. The high sorcerers pay good money for every thirsty one put out of its misery ...
