These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Complete Monster: Azazel is a sinister demon who likes nothing so much as destroying the lives and names of good men. When Detective Hobbes crosses him, Azazel sets about targeting him by possessing Hobbes's mentally handicapped brother and making him commit suicide. Azazel possesses others and murders others in their bodies, getting them convicted of murder and jumps out just before the execution, leaving the victim to face death for crimes they have no memory committing. Azazel destroys Hobbes' life and reputation and possesses people to continuously drive him mad from near paranoia. What's worse is Azazel has been walking the earth for thousands of years and his MO has never changed.
Foe Yay: Azazel, buddy, you need to scale back on your obsession with Hobbes just a smidge. And stop calling him "pal". And stop talking about how much fun you're having with him.
"I'll fuck you left, right, backwards, forwards, coming, going..."
Fridge Horror: The movie demonstrates that people Azazel possesses don't recall their actions while under control. Think back to Reese at the beginning, trying to possess Hobbes. Had he succeeded, the real Reese would have returned to his own consciousness minutes before his own execution for crimes he has no memory of committing.
This happens anyway, since he possesses a nearby guard instead.
Moral Event Horizon: Azazel possessing Hobbes' brother Art, who's implied to be mentally handicapped, to make him commit suicide by injecting himself with poison.
Paranoia Fuel: Azazel lives and breathes this trope. He can freely possess anyone who doesn't have strong enough willpower to resist him with a touch. In a crowded area he can be anywhere in moments. And if you kill one of his hosts he can just possess anyone he likes. He turns normal people into serial killers and does it purely For the Evulz. And it could easily be you next.
The Woobie: Plenty of Azazel's hosts qualify, Charles being a very notable example.