Catharsis Factor: Katie does give up on trying to convince John that there is something wrong with Esther, saying that it's if he wants her to leave, but only on the condition that Esther goes too, which is pretty satisfying.
Designated Evil: Esther's mercy-killing of the accidentally, mortally wounded bird, is presented as a cruel/heinous act. While it makes Esther seem like a Creepy Child, it's much more out of apparent cold pragmatism than anything inherently evil.
Esoteric Happy Ending: Given her overall incompetence and the fact John is now dead, it's possible Kate will not be allowed to keep her kids after the events of the movie. That said, the fact that Esther will have been proven to be something she totally wasn't could still make a difference for events moving forward though.
Among the small amount of fanfictions that exists for this movie, the most often repeated plot involves John giving in to Esther's advances near the movie's climax.
There's also this incredibly bizarre and dangerous cult, the Grail Movement, whose leader, Barbora Skrlova, has a glandular problem that causes her to look like a child, to the point she was able to legally change her identity to that of a thirteen year old named Anicka to elude authorities.
Danny being threatened by Esther with castration as she taunts him for his lack of sexual inexperience and turns out be an adult woman becomes harsher after his actor, Jimmy Bennett, accused Asia Argento of sexually assaulting him when he was 17.
It Was His Sled: Esther being a 33 year old dwarf will catch on even if people haven't seen the movie thanks to the internet.
Jerkass Woobie: Danny starts out as a brat, but you can feel genuinely sorry for him. He's dealing with a psychotic adoptive sister who tries to kill him multiple times. Even if he was rude to Esther in the beginning, it turns out he was right about her.
Jerks Are Worse Than Villains: John, the clueless adult who trusts Esther more than his own wife and used to cheat on her ten years ago, is more hated than Esther herself, the Evil Orphan who wants to kill the whole family.
Karmic Overkill: Sure John was a jerk and an idiot, considering that he was overtrusting of Esther/Leena but he didn't really deserve to be stabbed to death considering that it happened right after realizing the truth about Esther/Leena.
Love to Hate: Esther is a very compelling horror villain for being smart and dangerous, as well as for her actress giving a great performance.
Moe: Max, to the point you would want to hug her in every scene she is in.
Paranoia Fuel: This film raises the point that you never really know the full truth of who you are adopting, and they could be a psychopath.
Rooting for the Empire: It's easy to root for Esther despite the fact she's batshit insane because A) She's a great villain and B) Isabelle Fuhrman's performance. Not to mention most viewers found most of the protagonists (except for Max) whiny and annoying.
The Scrappy: John's stupidity, blind trusting of Esther, cheating on Kate after the stillbirth of their child, and myopia towards all the horrible events that had been occurring since Esther was adopted made him quite unlikable among viewers, to the point that his brutal death comes and goes without much thought; the rest of the film is dedicated to showing the much more likable Max attempting to survive Esther's rampage.
Strawman Has a Point: Esther's killing of the bird is supposed to be evil and heinous, but her correctly claiming that the bird's fate is Daniel's responsibility and that it's suffering and should be put out of its misery make it come off as cold but correct Shoot the Dog.
The entirety of Kate's Nightmare Sequence, if not helped by the completely sickening notion of witnessing a fetus removal from a woman's body.
Sister Abigail's murder. When the police find her body, her face has been reduced to mush.
Esther breaking her own arm, especially as the bone very visibly pops out. The fact that it's the only scene where she shows any real weakness or pain somehow makes it worse.
This film's use of black lights. They reveal terrifying and disgusting, gruesome paintings, as well as sexually explicit paintings of John and Esther.
Esther, who is portrayed by an 11-year old, tries to seduce John in a sexually provocative cocktail dress.
Kate, who has just lost her baby, is mentally abused by her adoptive daughter for the length of the film and is hospitalized when her (perfectly justified) paranoia causes her to assault Esther in public.
Max has it worse. She is a 5-year old mute child who witnesses her new adoptive sister brutally murder an innocent nun and her own father, is almost killed herself in at least 4 separate occasions, sees her brother nearly burn to death and be suffocated, is chased by a psychopath into the woods and is forced to handle a firearm despite her young age. It's safe to say that the trauma from her childhood will haunt her for the rest of her life.
that makes it hard for her to walknote , was adopted by an Indiana couple in 2010, but shortly afterward her parents began (or at least claimed to) to suspect she was actually an adult. They claim that she had developed body hair and a menstrual cycle (which even if it is true, any doctor can verify precocious puberty exists), acted too mature for her age, and was murderously violent. They treated her like an adult despite getting the results of medical tests that backed up that she was only a child