Miko as a Blackguard, I don;t see it, I did before this point, but she's just a jerk, not a vengeful, coniving, evil piece of filth...okay, maybe she is vengeful, but definiately not evil and coniving, at least not yet.
I agree with Henry, I think she has to do something to not only regain the blue at the moment of her death but does so to save Roy so that he always carries that eternal flame for her (which is currently just a wet matchstick.) Of course, what would be even funnier is if later if Roy finds someone new she descided at THAT monet to come back as a 'ghost' like Roy's dad and nag him constently. "I saved your life and this is the thanks I get, you chasing some obvious floosey..."

Hint, Hint Rich, I want royalties.