Urzon wrote...
I'd have to disagree. Adralla (of Litany fame) was able to make all kinds of spells and items to counters blood magics, without actually having used blood magic herself.
Taken from the Litany's codex...
Adralla of Vyrantium dedicated her life to the study of blood magic—the academic study, rather than the practice. A deeply pious mage, she was renowned in her day for having found a counter to every form of mind control, a defense against dream walkers, and even counter-spells to demonic summons.
So she proves it's possible to counter blood magic without more blood magic. The Tevinters we see ingame don't seem to care.
I never said it was impossible either, although in fairness I'd completely forgotten the Litany. (For that matter, everyone else usually does too.) However, the Litany is flawed in that it can only interrupt a spell that's being cast, rather than one that is fully in effect.
As to making it common to counter blood magic without blood... it doesn't seem to be that easy. The only known researcher was Adralla herself, and she's dead. A non-Tevinter trying to improve on her methods would be suspected of the practice rather than the academic study (the templars outside Tevinter are
really stab-happy), and it looks like a Tevinter would be drawing a bullseye on the back of his/her head. And why not? The Tevinters don't seem to be capable of suspecting someone of self-less motives. They probably thought Adralla was just trying to get a leg-up. (And since the Codex entry is written in third person limited, how do we know she wasn't?)
While I can see some Magisters using even more blood magic to break and counter spells, it wouldn't be practical to sacrifice an X amount of slaves to counter spells in the daily life of a Tevinter Magister. There are political schemeing/backstabbing, duels against rival Magisters, and all sorts of mayhem. There wouldn't be any slaves left alive in Tevinter if they used blood magic to overpower spells for everything.
Well, blood magic isn't Caladrius's first resort when you attack him, is it? He only starts sacrificing soldiers when it becomes clear he stands a chance of losing, and only sacrifices the slaves as a deal to save himself when it becomes clear he's lost. He doesn't even want to fight at first. Unless the Warden forces a confrontation, Caladrius is happy to defuse the situation verbally. From what I understand, the same holds true for Danarius. The other strongest, more experienced magisters probably got that way partially because they're as good at avoiding fights as winning them, thus granting themselves time to practice.
Then there's the fact that magisters can't possibly have to fight off their rivals
every day. That wouldn't leave the slaves extinct, it would leave the
magisters extinct.
Besides which, a blood mage doesn't strictly
need to kill anyone to fuel his powers. He's quite free to sacrifice some of his own blood.
It just would be easier for them to read up on and study different spells, and them to develop their own counterspells and enchantments to defend against them.
It would be cheaper than sacrificing slaves, but if you mess it up, you're dead, and in a setting where resurrection is basically impossible. When it became obvious the Magisters wanted Adralla dead, even she decided to flee Tevinter, and she (literally) wrote the (non-literal, from the look of its icon) book on countering blood magic with the regular kind.