Ye Olde Writeup of Vivamort had an uneasy fusion between traditional
vampire lore and gloranthan vampires. Many details are left unexplained
- why can vampires turn into wolves, bats or clouds of mist? - while the
justification for others no longer convinces - if Yelm can curse
Vivamort then why doesn't he do the same for his actual murderer?
There's also a big tension about the nature of the vampires - do they
drink blood or drink souls? The RQ3 Vampire rules made this worse by
making them drink both blood and drain fatigue by touch, a clunky game
mechanic that doesn't convince. And we never got any information about
how one could be a vampire without going through Vivamort. OTOH the
Dancers in Darkness encountered in Sartar: Kingdom of Heroes work better
as vampires even though little detail is given about them.
I don't think the Vivamort ability to drain spells and other magic from
their victims is possible anymore. If detail were needed about their
magic and blood drinking, I would use the victim's runes as a guide to
the quality of the blood with certain runes being better than others (ie
from a Vampire's PoV Darkness is good while Fire, Life and Death are
Bad). Most blood is metabolized to feed the vampire's undeath rune but
some can be used instead to fuel magics (other than natural vampoiric
abilities) that the vampire might know or remember from his past life.
--Peter Metcalfe