At this point, trying to discover the nature of this raven is a bit out of our reach. First, to confirm whether he is a puppet or not. We've looked at the story, let's look at it again while taking in the stylistic aspect of the text;
-Why did the author decide to start this text with the boy walking in with a broken tibia?
-What is the importance of this wound?
-Well for one, the character in-game limps and needs a cane. We can therefore say that it is an important trait of the character design.
-Also, the wound was FRESH in the story. Out of all the wounds, why is it that it has not been repaired? Even when it was offered to be healed? (Therefore visibly heal-able)
-This implies that the wound either cannot be healed(Due to hidden reasons), should not be healed, or that he simply doesn't care.
-Have you ever not cared about a broken limb? That's right, me neither. And even if you could not feel pain, you would surely not turn down healing, just for ****s and giggles.
-If it can not be healed, it implies a special nature. Same if it should not.
-Therefore, if you take in the importance of the wound, and its treatment, you may, or may not come to the following conclusions.
1 - The events that caused the wound have a certain importance in the character story.
2 - This wound is either :
A - Supernatural/Special
B - Unimportant
HOWEVER, since the wound was examined and fixed by the healers, and nothing especially amiss was noticed, it would be safer to assume that the wound is UNIMPORTANT physically, even while being important for the story.
In this train of logic, this would lead to assume that considering he feels no pain, the storyline importance of the wound and the fact that the wound seems fairly unimportant(To him), it is safe to say that the RAVEN likely is in control, most likely related to X event that led to wound.
Now of course, my logic has quite a few possible holes, but the idea is to show that it is the most likely answer, rather than the absolute correct answer.
Could it be that the wound was caused by the Raven's sudden attack and attempt at possession? Or was he actually wounded in battle, and saved by the Raven? Did he make a sort of deal? Also, what to make of his hunger for power?