Now this was a real mind-trip of a story. I've never seen anything quite like it, and I actually felt myself get sucked in. I haven't felt like that in a long time.

Personally, I think the werewolf is real, starting at first as the manifestation of the side of Ryan's personality that seizes reality and makes the world his playground, then becomes physically real when they clash (in the basic sense) for the final time. It's what he wishes he could be were it not for his reluctance, and those pills didn't seem to do anything for him except cause more stress. When Ryan was made into its meal (or mercy killed), it became real for good and put his physical self under new management.

Regarding that other voice... I think that was his inhibitions talking to him. Those can keep someone from taking foolhardy actions and guide them to safety. However, they're also good at preventing one's true potential from emerging and locking out good risks. They were likely the reason Ryan was in pain the first and last times the werewolf took over, and when they weren't as active, the take over was painless. The fact that he didn't listen to that voice until it was too late tells me he was tired of his gilded, safe lifestyle and wanted one that met his needs.

Sorry, I couldn't help but analyze the whole thing. It was phenomenal and really got my mind going.