Death Seeker: During the Season 3 episode I'm so Lonesome I Could Die.
Defiant to the End: Mixed with Heroic Sacrifice. When it becomes clear he isn't getting out of Liam's torture chamber alive, Aidan tries to protect Nora by lying about having killed Brynn, taunting Liam about how she begged for mercy. Josh manages to rescue him in time, but not before Liam gives him a shot of infected blood.
Our Vampires Are Different: Immortality and everlasting youth, sure, but Aidan and the other vampires can tolerate some sunlight if they have protection. They have reflections, too. The former may make sense since vampires didn't 'develop' the burst into sunlight aspect until the movie Nosferatu; thus in this universe, while people believe vampires are affected by sunlight, it may not be as bad as that. And as Aidan notes at one point, they simply must have developed a resistance. Season 3 introduces the "virus", an influenza virus that kills vampires in days after drinking the blood of a human who had the particular flu. The only cure is werewolf's blood, which normally causes seizures and pain after consumption. Aidan also notes that the blood of a revived corpse would also not sustain him.
Badass Normal: During the time that he's cured. The self-esteem and perspective he gets following the events of the season 2 finale end up pushing him to become the most heroic member of the cast in season 3.
Humans Are The Real Monsters: While Josh would fervently deny this, almost all the destructive and selfish things that he's done have been a result of his decisions as a human, not his lycanthropy or actions as a wolf.
Only Sane Man: Of all the characters in the show, Josh is easily the one that tries hardest to be human.
Our Werewolves Are Different: Werewolves change only during the full moon, during which time they are completely subsumed by the wolf. Afterwards, Josh professes he has no clear memory of what happens, only recognizing the side effects of his transformation after, like his regurgitation of the small animals he had eaten the night before. However, Josh's inability to remember what happens may actually come from Josh's abhorrence at his lycanthropy, as other werewolves who have embraced it seem to remember everything perfectly. His wolf is perfectly able to remember Nora after transforming, seeing her as his mate, but otherwise the wolf is a murderous beast. Werewolves also experience heightened strength, senses (smell in particular), tenseness, and libido the days leading up to the full moon.
Papa Wolf: Josh has become one for his adopted family. Ironically, he's more of a wolf as a man protecting his family than he ever was as an actual werewolf. Even Liam is impressed.
Status Quo Is God: Spends most of the third season as a human once he kills Ray. Comes to an end when he attempts to save Aidan and winds up getting injured by Liam.
Took a Level in Badass: After he kills Ray. The submissive, non-confrontational Josh of the first two seasons is gone in season three, replaced by a Josh that is confident and not afraid to face danger head-on (or even to take a life) to protect his family.
Our Werewolves Are Different: It would seem that wolves turned from humans with a lot of emotional baggage (an abusive boyfriend, in Nora's case) are even more violent, since their built-up anger is not inhibited in wolf form. Nora also reveals that she can remember everything from her transformations, which is probably due to her being more accepting of the transformation than Josh.
A young ghost who is dealing with abandonment issues.
Ambiguously Bi: Sally tends to come off as this on occasion. For instance while talking at Emily, Josh's sister, she says she could make her feel happy. And when Nora comes over, Sally promptly quips that she's hot and has nice boobs.
Ambiguously Brown: "Get Out of My Dreams, Get Into My Mouth" revealed she is at least part Indian (as in South Asian, not Native American).
Axe Crazy: after it's revealed that the Reaper is actually her.
Refusal Of The Call: In Season 3, Sally no longer wants anything to do with trying to help ghosts and other people as it has always ended badly for everybody. She goes so far as to disperse ghosts who try to ask her for help.
Sanity Slippage: Season 2 reveals that she began going insane after missing her door.
Humans living in Boston who interact with the cast. They don't generally stay human very long.
A young boy from the neighborhood Aidan befriends. Killed when he walked into the street and was hit by a car. Rebecca turns him thinking it would make Aidan happy, but Aidan later kills him because he's made to believe Bernie can't control himself.
A teenaged boy born with a severely weakened immune system that lives in a glass enclosure in the hospital to protect him from disease. Since he has had almost no contact with germs throughout his entire life, Aidan uses him as a supply of clean blood.
Bubble Boy: Portrayed completely seriously. He eventually comments that what he has is not a life, and he will walk out of the room when he turns 18, or Aidan can turn him.
He also hates it when people call it Bubble Boy disease.
Came Back Wrong: Because he was vamped with cursed werewolf blood, Kenny came back as an extra hungry, extra disgusting vampire.
Genre Savvy: There isn't much to do in his enclosure other than watch movies, so he recognizes Aidan as a vampire almost immediately.
From Nobody to Nightmare: As a human, Henry was rather timid and tame, if expressing curiosity and desire to experience being a soldier and killing. As a vampire, he's cocky, bold, and perfectly willing to act on his ambitions and killer instincts.
Come season 3... he's glamoured a human girl into being complacent with being imprisoned so that he has a supply of untainted blood to survive on.
Mind-Control Eyes: Standard for vampires, but Aidan often had Henry do it for him because Aidan himself is terrible at it.
Normally, I Would Be Dead Now: Henry is harder to kill than a cockroach. He served in World War One, was a fugitive from the vampire world for eighty years, got skinned, extricated himself from a meat hook, and when the plague came around, he still wouldn't die. The plague eventually does him in, though.
Two purebred werewolf twins that offer to fund Josh's research.
Affably Evil: Brynn. According to Nora when running off with her off-screen she is much more sadistic.
And I Must Scream: They describe their human existence like this. Josh is uncomfortable with heightened senses and moods the few days before a full moon, they feel that way every moment they're not wolves.
Bullying A Vampire: Taunting Aidan was probably not the best move, Connor. Especially since he had a rifle loaded with silver bullets.
Killed Off for Real: Both of them. Connor was first killed by Aidan and later Nora killed Brynn during the time she ran away with her.
Morality Chain: Nora suggests that Connor was this to Brynn, not the other way around. Of course, this is a relative chain since Connor's idea of a good time is torturing vampires and hunting them down for fun. One can only imagine what Nora might have seen Brynn do without Connor's influence.
It's suggested that it's torturing and eating humans.
Our Werewolves Are Different: They're pure-bred werewolves whose senses are constantly heightened, not just a day or two before the full moon.
Brynn and Connor's father, who comes to Boston in the third season to try and find out what happened to to his son and daughter.
Anti-Villain: If you think about it, extermination of all vampires WOULD probably make the world a better place, and much of his motivation comes from love for his children, but he's also a major antagonist.
On the other hand, he also has very little regard for humans so in that sense, he's not really any better than the vampires he claims to be superior to despite his other claim of being part of 'nature's will'. Plus, despite being concerned with the safety of werewolves, he doesn't really show other werewolves any particularly regard either, generally using them as pawns or tools by pushing his dominance over them.
Badass: He was introduced into the show by killing an entire room full of (admittedly sick) vampires.
Evil Counterpart: Well... eviler anyway to Bishop. Both are very similar in a lot of ways but Bishop at least made the attempt at being civil and civilized. Liam clearly partakes in human culture because of necessity or because it's useful.
Fate Worse Than Death: Combined with Our Ghosts Are Different, because he died in a drowning accident he relives the moment of his death, being strangled underwater and drowning all over, again, culminating in an explosion of ghostly water.
He later ends up being "reaped" by Sally while she's under the influence of Scott, and is sent to Limbo where he is forced to keep drowning except for the times Sally manages to pull him out to try to escape.