Queen-Of-Stuff wrote...
The problem with the notion that Justice could know how to use blood magic is that Anders would know it as soon as Justice entered Anders' body. Everything that Justice knows, Anders knows - for them to keep secrets from one another is impossible.
To be honest, I don't really agree with Merrill's assessement of spirits and demons. I mean, sure, if you look at their most basic traits, they share the same characteristics - they are beings native to the Fade, they can see into the minds of mortals, they can shape the Fade to their will and inviting either to take up residency in your body is the Worst Idea Ever, but. There is a difference in their intentions - demons wants to live in the world of mortals and so use mortals for that purpose by encompassing their "vices" and preying on their weaknesses. Spirits, on the other hand, care more about the whatever human virtue they have chosen to embrace, and this is true for Justice as well, even as corrupted as he is.
I used to think that demons were necessary to unlock the power latent inside blood, but I've since changed my mind. The problem I have idea that blood magic is knowledge innate in whatever basic form spirits and demons are is that they don't have blood. It's a power entirely dependent on the flesh - as the codex entry on the matter says, it doesn't require drawing power from the Fade. If it originated from an Old God or the elves, it's plausible to think that demons would be interested in harvesting knowledge about it so that they can use its power as a bargaining chip in deals with other mortals. Spirits have no reason to be interested in it.
I'm with you on spirits vs demons. Demons = bad, spirits = good. But inviting either inside your head just isn't smart. It's obviously more dangerous with demons than spirits. I think of fade spirits in about the same way I would angels from Christian tradition. They might be the good guys, but they're also destructive forces of nature, capable of violence on a scale a human mind can scarcely comprehend. Inviting that to bunk in your noggin is asking for trouble.
As for justice, I think he's merely a spiritual rendition of what has already happened to Anders. Anders is a man who believes in justice, but the unchecked injustices of the templars finally broke him. The spirit Justice is not so different, once it was in Anders's head and was able to directly experience the same injustices Anders had for years.
Personally, I don't have a particular problem with Anders/Justice uncorking a whole case of holy retribution on the templars. They've earned it. There is a season for all things, including one for making war. Even madness has its place at times in the service of what is good and right.
As for blood magic, I suspect demons find it interesting because it's an analogue of what they do. Demons draw power from their own spirit, their own life force. Blood magic operates on a similar principle. It's not about blood, per se, but about using life force as a fuel source. For a human to do so apparently attracts the attention of unsavory spiritual entities and pretty soon there are abominations all over the place eating everyone's brains.