Abduction Is Love: Alec paralyzing and abducting Bree from her hotel room to "have a conversation" with her.
Affably Evil: Alec at one point kidnaps Bree with his powers, tries to tempt her back into human blood, insults her coven openly, chases her all the way from Sibiu to Cluj-Napoca and then tries to get her to talk about common interests with him.
Subverted because He is most likely going to get the girl in the end.
At Least I Admit It: Alec is pretty comfortable with who he is and makes no apologies for it.
Attention Deficit... Ooh, Shiny!: Santigo, but he uses it to his advantage, organizing documents, operating computers, locating vampire law infringers, monitoring the world, playing Video Games, shopping online, and falsifying international information with one hand, and solving a Rubix Cube with the other.
Boring, but Practical: Bree's vampire power is to be able to sense intentions and to be believed when she telling the truth or certain truths. Not flashy, but useful.
Jane: You never ask what I would do if anyone destroyed you.
Alec: That's because I always assumed you would find a nice hourglass for me.
Demoted to Extra: Bella and Edward's roles have been reduced to welcoming Bree into the family and Edward talking to Bree about the wedding. Justified as there are small hints that the events of Breaking Dawn are still taking place while Bree is off doing her own thing.
Eats Babies: The coven Alec and Jane execute in "Precocious Prizes" are guilty of doing just this, but the Volturi are mad not so much because they did it as because they did not clean up after themselves.
Even Evil Has Standards: Alec is shocked and offended by the suggestion that he might have molested Bree while she was incapacitated by his gift.
Bree: Okay, I'm sorry I implied that. Just because you're a remorseless killer, a stalker and a kidnapper doesn't mean you're also a sex offender.
Corin semi-qualifies. She works for the Volturi and drinks human blood but doesn't like making them suffer so much so she'll twist Alec's arm into using his talent to avoid causing her meal fear and pain.
Hannibal Lecture: On multiple occasions Alec deconstructs the Cullens' value of human life and their desire to imitate it in ways that make them appear far less noble and benign than portrayed in the book series.
During a phone conversation with Alice Cullen, Alec offers a disturbingly alternate view of the Cullen family that depicts them as a cult pretending to be a family who's love and acceptance is entirely dependent on their members' obedience to their diet and human-friendly philosophies. He also accuses the Cullens of forcing their views onto Bree - an impressionable, newborn vampire - and pressuring her to conform to their lifestyle to the point of (unintentionally) physically and emotionally abusing her.
Possibly the most horrifying observation Alec makes of the Cullens is that their inaction against the growing newborn army during the events of Eclipse and singular desire to protect Bella Swan resulted in hundreds, if not thousands, of innocent humans (such as Bree herself) dying to build and sustain Victoria's newborn army, all so Bella could have a few extra months as a human being. Which certainly makes the Cullens sound like a bunch of selfish hypocrites when it comes to their criticism of other vampires lacking respect for human life.
Ironically, Alec's motivation for saying all this seems to be a genuine desire to alleviate Bree's physical and emotional anguish as well as bolster her self-esteem and independence as a vampire. Something the Cullens are, arguably, not doing despite their professed love.
Immortal Immaturity: Vampires have a tendency to act their physical age, though their actual age and personal experiences can curb these impulses and allow them to behave maturely.
Alec, for example, carries himself like an adult most of the time but has a few habits befitting a teenager such as: teasing people, taking himself too seriously, overreacting when frustrated, fantasizing about killing his problems away, acting out when he doesn't get his way, handling rejection poorly and stalking Bree around and spying on her, wanting to keep her all to himself and feeling easily jealous of and threatened by anyone he considers to be romantic competition
Lawful Evil: Volturi FTW, though they love their loopholes.
Alec often uses the Volturi's peace-keeping as a sanctioned excuse to eliminate potential problems, such as using the fact Fred was a member of the Seattle newborn army as an excuse to kill him, if necessary. Or that he gets a pass on plotting to murder Seth Clearwater because Alec originally assumes he's a human who knows about vampires only to later learn he is, in fact, a werewolf.
Legal Jailbait: Jane and Alec have been 14 for close to 350 years
Bree, conversely, is mental-minor for 2 more years since she's a 16 year old trapped in a 15 year old's body.
Manipulative Bastard: Alec prefers constructing elaborate roadrunner trap scenarios in order to spend time with Bree rather than simply going up and talking to her.
At one point Alec contacts Santiago to cut all phone communication off between Bree and the Cullens to hinder Alice's ability to warn Bree about any visions she might have pertaining to Alec's scheming. Worst yet. Alec encounters Fred and - upon uncovering his friendship with Bree - directs Fred to Volterra to hold him as a bargaining chip for Bree to spend time with him..
Meaningful Funeral: Bree holds one for Diego in the underwater cavern they once shared. She gives him a moment of silence for every moment she knew him. Intense sadness issues.
Alec: My mind flashed images of the ten most gruesome deaths I ever witnesses and I contemplated which one to replicate with this boy.
My Beloved Smother: Esme, dear lord. Granted, she generally keeps it down enough that it's more sweet and slightly humorous than stifling.
Noble Demon: Alec has one of the scariest reputations amongst vampires yet he can be down-right-decent to people like Corin, Bree, Jane and the driver Santiago hires for him without fully discarding his more devious qualities.
Not Growing Up Sucks: Alec has stated several times he is not thrilled to be in his early teens forever and Bree is gradually appreciating how frustrating it will become.
It hasn't been specified whether Jane is unhappy with being 14 forever.
Stalking Is Love: Alec seems to think so, going to the vampire radar Demetri to lend him aid in tracking down Bree, however unlike Bella Bree openly calls him out on it after he kidnaps her.
If two of the three in the triangle are vampires dose it still count?
Vegetarian Vampire: She's working on it and falls off that wagon in "Alaska or Bust".
Walking the Earth: So far Bree has been to all over Washington, through Alaska, parts of Romania, and, if Alec gets his way, Italy soon as well.
Well-Intentioned Extremist: Jane, she does not understand why she can’t be both a Serial Killer AND a Champion for her kind.
Alec wants to save Bree from the Cullens' emotional manipulation . . . by sending her friend to Volterra to use as leverage. Despite his claims of not being a hypocrite, unlike those damn Cullens, one has to wonder if he's really thought this through . . .
Wicked Cultured: The Volturi are famous and respected for this by other vampires, even the Cullens.