Sometimes it confused Severus. Lupin was the monster, the werewolf. He was a beast, not human. So why was he the best of them?
Severus hated Potter. He had humiliated and tormented Severus from the very first time they met, on the train to Hogwarts. In front of Lily, no less! It had only made her dislike Potter, but…Severus knew that Potter's treatment of him, and how powerless Severus was to stop it, was the reason Lily didn't love him back. How could Lily, wonderful, beautiful, brave and noble Lily, love someone who couldn't even defend himself from an idiot like Potter?
Severus despised Black. He knew Black was the driving force behind the group. Black hated him because the imbecile had decided to go against his family, and Severus was distantly related to that family. Never mind that Severus was an outcast from the pureblood society, too, because of his horrible father. Black didn't know, and Black didn't care. Black just wanted to hate someone, and the others hated him because Black did. They might have left him alone if Black wasn't out looking for blood.
Severus scorned Pettigrew. He was a weakling, content to go along with his friends because he had no imagination of his own. He was reasonably talented, magically, but too scared to reach out and take what could be his. Or too dumb to realize the power he could have had.
Severus feared Lucius. Lucius was currently trying to get him to join that group, the one the guy with the stupid name had. Severus didn't really understand it all, but Lucius and the Malfoy family were so powerful that Severus would probably join just to get him to leave him alone. Malfoy kept going on about what Voldemort could offer him if Severus helped him. Severus just wished Malfoy would mention what it was Voldemort wanted to do in the first place.
Severus was miserable in Slytherin House. Again, all Potter's fault. They were a house that prided themselves on ambition. On never backing down, on taking what you wanted. On having, perhaps, slightly loose morals. Severus was seen as weak, because of what Black and his friends did, and he was scorned and alienated because of it.
But Lupin…Lupin was a monster. He was out for human blood. He couldn't be expected to control himself. So why was Lupin the one who hung back, who never participated in the taunting and pranking? Why was Lupin the one who eventually made it stop?
Sometimes it confused Severus.