I'm rewatching this show and I'm disappointed by how little they used Hallucifer over all. He is an amazing character that singlehandedly improves the episode by a lot every time he is on screen. The dynamic he has with Sam is very interesting and seeing how the hallucinations affect Sam from this perspective is much better than just hearing about it every few episodes. It's also a shame they didn't use it for more than Sam having hallucinations and feeling terrible after this episode showed that Hallucifer could become a part of his subconsciousness and influence the way he acts directly. Despite the fact that you can see Sam observing and processing the crucial details at the same time Hallucifer is talking about them, it's easy to be fooled into thinking that it was something else than his own mind giving him hints, which makes this Lucifer feel much more real and harder to ignore by Sam - a clever way to have Hallucifer reenter the scene and not go away anymore. What I'm trying to say is that this was a great reopening of that great, but underused plot line. Also the A plot, Jeffrey and the demon, had an great earlier Supernatural vibe with something fresh added.
There's really just 3 problems I kind of have with this episode. Starting with the least important one, I don't understand how did they paint the last devil's trap, it makes absolutely 0 sense. It's not the only time this show just dumps a surprise pentagram on you, but they didn't even try to explain how they drew it without Jeffrey hearing or seeing them. The red herrings around Jeffrey worked well and it was heartbreaking to see such a good guy turning out to be a serial killer obsessed with the demon that possessed him. However some of his lines towards the end were weird. How would he know how Dean is feeling about saving the world and why would that be what is he talking about? It felt shoehorned in. Also this episode should have been a wake up call for the brothers about how their actions can impact normal people after the monster is sent away, but that is never brought up again, so focusing on it this episode seemed counterintuitive. But these are just small details, not enough to bring down the episode significantly.
There's really just 3 problems I kind of have with this episode. Starting with the least important one, I don't understand how did they paint the last devil's trap, it makes absolutely 0 sense. It's not the only time this show just dumps a surprise pentagram on you, but they didn't even try to explain how they drew it without Jeffrey hearing or seeing them. The red herrings around Jeffrey worked well and it was heartbreaking to see such a good guy turning out to be a serial killer obsessed with the demon that possessed him. However some of his lines towards the end were weird. How would he know how Dean is feeling about saving the world and why would that be what is he talking about? It felt shoehorned in. Also this episode should have been a wake up call for the brothers about how their actions can impact normal people after the monster is sent away, but that is never brought up again, so focusing on it this episode seemed counterintuitive. But these are just small details, not enough to bring down the episode significantly.