A sacrifice done for the right reasons brought tons of power but you had to raise the animal, treat it better than you treated your own family and honor it after you killed it. Most people who wanted the power didn't care about doing it right.
"Not really." He leaned back against the bench to study her. She definitely had the earmarks of someone with hero tendencies. That was always a bad sign when one of them showed up in his path. The universe was a huge meddler.
"Look, anyone can fight the people who do a little blood magic and do bad things. Even someone without magic can learn that." He waved a hand around indicating the entire city or possibly world. "I'm what's known as the big guns luv."