I dunno... I have NEVER heard of a non-malicious blood spirit. They go free and it's a blood-sucking, essence-draining rampage. And Street Magic seems to indicate Blood Magic almost inevitably Twists it's user...
Ah, but you're not going to convince me most Great Dragons havent tried giving it a whirl, or a few other big players like the Immortal Elves.
Some of 'em? They most certainly have. But remember, magic was different back in the
Earthdawn days, when a splash of blood was par for the course for an awful lot of mojo.
Like Aina, in
Worlds Without End, right there in the big action scene, when she bleeds herself to power an offensive spell...and it works. The spell's more powerful, the bad guy gets zapped. Good for her! But she
does acknowledge the seduction of it, later. She does know that that powerful a display of magic, even fueled by herself, caused enough of a mana spike to bring the Horrors closer. She does know that what she did was wrong, even though it was necessary...which just reinforces, not contradicts, the idea that blood magic is the province of NPCs who are twisted or are flirting with it, not just another handful of metamagics that every PC should have access to. Don't forget, Dunkie himself --
Shadowrun's own Christ figure -- offered a cool million a head bounty on blood mages. That should tell you that the universe's moral authority sees 'em as pretty bad and dangerous.
I think the last thing
Shadowrun needs are hordes of Drizzt clones, swarming masses of Blood Mage PCs who are "the one good Blood Mage," running all over the place angsting about their dark heritage and stuff. Blood magic's been listed in the "Magical Threats" type chapter of the magic books for multiple editions now, which pretty clearly marks it as "for the bad guys" territory. I know some people always have the urge to play the exception to every rule...but by and large, these rules are in place for a reason.
