"...blood magic is almost always dark magic, Sev." And he knew Sev knew that. Sirius was oblivious at times, but he wasn't naive. Besides, he had listened to enough of James' rants about Severus and he knew that his friend had a point. He could imagine what James would say if he found out about this. "We are always gonna be friends. I think friendship is magic as it is. No spell needed. Like love, right?"

And, no, he didn't like the feeling that he was backing away from a challenge here. Nor did he like disappointing a friend.