Badass: He's supposed to be, but it's subverted due to him being a general Non-Action Guy. Played straight after returning from the Real World however.
Badass Pacifist: His secret weapon to defeat Lord Business is his hand and a speech.
Becoming the Boast: While he doesn't knowingly brag about being "the most important, talented, interesting, and extraordinary person in the universe", he still manages to impress those who genuinely fit those qualities better than he does, ultimately making himself a hero to the people thanks to the faith his position as The Chosen One gave him.
Blank Slate: Deconstructed; Emmet has so little self-characterization that his peers have very little to say about him, let alone remember him by. One of the minifigures who are interviewed about him even call him a blank slate. It's later reconstructed as the blankness of his mind gives him limitless potential to create anything he wants. It also helps him hide, because his face is so nondescript that every possible face in the LEGO universe fits his profile. Justified in that his face is the original bog-standard Minifig face from years ago (when not expressing).
Butt Monkey: His so-called friends hardly even know he exists, and several of his allies only really stick around him because the key to destroying the Kragle is literally glued to his back. He does eventually gain some respect as his seemingly dumb ideas prove invaluable to his team's survival.
Came Back Strong: After returning to Lego land he has the abilities of a full fleshed Master Builder; building massive constructions on the fly, and enforcing Conservation of Ninjutsu on the robot mooks.
The Chosen Zero: It's painfully clear how much more qualified all of the Master Builders are at being the Special than he is; he's naÔve, idiotic, clumsy, and can barely muster the creativity to put two tiny LEGO bricks together. It later turns out there's no such thing as the Special; it was all a ruse devised by Vitruvius to make him see that anyone can be special.
Clingy MacGuffin: The key to neutralizing the Kragle, the Piece of Resistance, is literally glued to his backside.
Closest Thing We Got: He's just an average Joe who gets in way over his head when he touches the Piece of Resistance labeling him as the Special, but since the Piece is irremovably stuck to him, the Master Builders have no choice (other than turn tail and run, as most of them do) but to follow him.
Crazy Enough to Work: According to Metal Beard, Emmet's ideas are so dumb that Lord Business would never expect them to work, which is exactly what they need to stop him.
Distracted by the Sexy: He often slips into this when talking to Wyldstyle early in the movie, ignoring her exposition and instead hearing her say how attracted she is to him.
Distressed Dude: Finds himself as such when captured by Bad Cop/Good Cop until he is rescued by Wyldstyle.
Dumbass Has a Point: For all the flak he gets for his lack of creativity, he does accurately assess the Master Builders' weakness (rampant individualism makes for poor teamwork). He also devises a plan that takes advantage of the individual team members' skills to infiltrate Lord Business' headquarters in a way he never saw coming.
The Everyman: In-universe. The audience actually gets a view of his personality more closely throughout the film.
The Fool: He pretty much fits this in all aspects: he takes a long while to catch up on the mess he's gotten into, let alone recognize how evil President Business is, and his most ingenious creations and antics are only the result of pure luck.
The Generic Guy: Deconstructed, seeing as though nobody thinks much of him at first.
Genius Ditz: A fool he may be, but he turns out to be more insightful than people give him credit for, especially when he suggests they start following instructions that still give free reign for the Master Builders to be as creative as they need to.
The Heart: For the Master Builders, he's generally considered worthless and uncreative, but he's also the one who keeps the group together, since their plans literally fall apart when he's unable to help.
The Hero: Most people think he's this as the Special, but in truth he has to learn how to be one.
Heroic BSOD: This happens to him a few times in the film: first is when he realizes that everyone around him considers him a nobody, and again when Vitruvius tells Emmet he made up the prophecy.
Hidden Depths: Already at the beginning of the movie he has some surprising moments of insight, such as realizing that Octan making among more innocuous products surveillance systems, all the history books and voting machines is in fact quite sinister. Unfortunately he's distracted before he can fully ponder the implications.
I Just Want to Be Special: Not at first; in fact, he's quite happy and content with his life. When he learns of the prophecy, however, he really wants to be the guy everyone expects him to be.
I Just Want to Have Friends: While he doesn't dwell on it until it's forced in his face, he's a fundamentally lonely guy who does his best to connect with everyone around him. He later admits that the reason he wants to be the Special is so that at least one person will find him worth being around.
Idiot Hero: When he, Wyldstyle, and Vitruvius enter his mind, they see it as a "prodigiously empty" landscape; Wyldstyle even opens a trapdoor on the ground and finds a cobweb inside. As it turns out, this allows him to have a clear vision of "The Man Upstairs" whereas his fellow Master Builders have spent years trying to clear their minds just to get a glimpse of him; after all, you can't clear a mind that's already empty.
Leitmotif: If you listen carefully, you can hear Emmet's leitmotif in a lot of soundtrack pieces, including the end credits. The most sterling example would be the triumphant reprise when he's storming through Bricksburg in his Humongous Mecha.
Lightning Bruiser: When he becomes a Master Builder, this is his niche. His mech is just as awesome & powerful as the other Master Builders' creations, but it adheres enough to proper building code to be as durable as the Kragglized vehicles.
Meaningful Name: "Emmet" is an archaic word for "Ant." Emmet resembles an ant in many ways, being just another cog in the machine with no individual personality.
Messianic Archetype: Outside of the whole "The Special" thing, in the end, he's an average commoner with a group of followers who sacrifices himself to save everyone. He then Came Back Strong soon after his sacrifice.
Mistaken for Badass: As the Special, people expect him to be some kind of genius Master Builder. In reality, he can hardly build anything without a set of instructions. At first.
Nice Guy: He is polite and generous to literally everyone he meets. As a matter of fact, his niceness is what saves the world from Lord Business in the end.
The Nondescript: Bad Cop/Good Cop has trouble finding him due to having one of the most generic faces in the LEGO universe.
Non-Standard Character Design: Unlike the other characters, Emmet's Black Bead Eyes are solid black and do not shine to reflect how early generation LEGO minfigs looked (this is also why Benny has them) and as a testament to how unremarkable he is.
Ridiculously Average Guy: Deconstructed; he's so generic that even people that speak and work with him every day can't identify anything unique about him. It's later reconstructed as this realization spurs him to become the Special, and also gives him limitless creative potential. It's also Justified as he is the Author Avatar of an average eight-year-old boy who is still expanding his creativity.
Rousing Speech: Subverted; he's brought up to make an encouraging speech before the Master Builders that quickly devolves into an Overly Long List of reasons why the Master Builders are thoroughly screwed to have him as the Special, intending to build up the impact of when he does begin to rouse everyone, but the crowd turns on him before he has a chance to.
Second Love: He is this for Lucy, with Batman being the first.
Seemingly Profound Fool: People think his "useless nobody" thing is just an act to avoid detection as the Special, not realizing he is a useless nobody.
Metalbeard: This here bedoubled land-couch. I watched as Lord Business' forces completely overlooked it. Which is why we need more ideas like it...
Emmett: Oh, thank you -
Metalbeard: Ideas so horrible and bad, that no one could possibly think they could be useful!
Something Only They Would Say: Inverted; Wyldstyle realizes he's not the Special when he start saying things the Special wouldn't say, namely that escaping the city is against the instructions; it all goes downhill from there.
Wyldstyle: Wait... What's your favorite restaurant? Emmet: Any chain restaurant. Wyldstyle: Favorite TV show? Emmet:Where are My Pants? Wyldstyle: Favorite song? Emmet:(singing) Everything is awesome! Wyldstyle:Oh, no.
The Strategist: For all his bumbling, Emmet manages to serve as this for the heroes when he concocts a solid plan to sneak into Octan Tower.
Broken Bird: A lesser form of the trope, but the whole "trying to shut her emotional problems by becoming Badass" deal is still there, as Emmet notices.
Defrosting Ice Queen: She's dark, brooding, and puts down others' ideas a lot, especially Emmet's once she clues in he's not the Special. However, she gradually grows more sympathetic towards Emmet and impressed with his crude yet ultimately successful creations.
Fail O'Suckyname: She tries to make her name sound cool, but all it does is make people think she's a DJ.
Given Name Reveal: Her real name is Lucy. She reveals this to Emmett during their attempt to disarm the Kragle.
Hartman Hips: She has a regular LEGO body, but she has Hartman Hips painted on, as is standard for female minifigs.
Hidden Depths: She's an unquestionable Badass, but she's also insecure and has changed her name on countless occasions because she couldn't face her true self. She's also not quite the fanatical believer in the Special as she first appears to be, rather wanting to be the Special herself, and is hurt when it turns out to be Emmet.
I Have Many Names: She's changed her name a lot in the past: Darkstorm, Gemini, Neversmile, Freakface, Snazzypants, etc.
I Just Want to Be Special: She sought out the Piece of Resistance because she wanted to be the Special, but the seemingly less qualified Emmet found it first, much to her frustration.
Jerk with a Heart of Gold: She may consider Emmet to be little more than The Load, but underneath that guise is a truly sweet and lovable person with the name of Lucy.
Jerkass Realization: She appears quite embarrassed of her harsh treatment of Emmet when he calls her out on it. She also apologizes to all the people in the LEGO universe for looking down on their supposed inability to think for themselves after witnessing firsthand how great Emmet's ideas could be.
The Lancer: She's Emmet's closest ally and wanted to be the special in his place. She's also the one who briefly takes over as The Hero after he "dies".
Noble Bigot: She fights to save the world and everyone in it in the name of the Special, but also looks down on people like Emmet who aren't Master Builders, thinking of them as mindless sheep who can't do anything without instructions. After acknowledging Emmet's creative potential through his heroic deeds, however, she pulls a 180 on her tone and begins helping other non-Master Builders realize their own untapped potential.
Phrase Catcher: Everytime she introduces herself someone asks "Are you a DJ?"
Sour Supporter: She makes no secret of her lack of faith in Emmet after discovering he's not the Special or even a Master Builder, accusing him of "ruining" the prophecy. In truth, she wanted the Special to be her, and being passed over for someone much less competent than herself burned her deeply.
Tall, Dark and Snarky: She's got a sharp tongue and has a keen interest in "dark and brooding" people like Batman.
Unresolved Sexual Tension: She's gradually getting attracted to Emmet over the course of the film, but her relationship with Batman keeps her from acting over it. Batman eventually lets her.
Bond Villain Stupidity: He includes a countdown and then leaves when about to kill Emmet instead of killing everyone right away while he personally keeps watch. In fact, he leaves no one in the room, except for the computer who does nothing. More points detracted when he leaves Bad Cop to die at the critical point where his plans are about to succeed instead of getting rid of Bad Cop after everything is settled. Predictably, Bad Cop helps the heroes right after.
Card-Carrying Villain: The flaming horned helmet, flowing cape, and evil minions all around should be a tipoff.
Clark Kenting: A "Behind the Bricks" shows he's pretty muscular under that suit.
Combat Pragmatist: If there is a simple option in war, Lord Business will almost always take it.
Control Freak: He's obsessed with having everything in a specific order and plans to use the Kragle to mold the world just the way he wants to. This is because he's similar to Finn's Control Freak father who is also incredibly anal about his LEGO.
Large Ham: Although he's mostly Faux Affably Evil he does have a couple of moments of being hammy, more notably at the beginning of the movie.
Lord Business: "Now my power will be unlimited! Can you feel me?!"
Laughably Evil: He can be rather hilarious at points, but still vicious.
Man of Wealth and Taste: As much as a LEGO figurine can be, anyway. Lord Business prides himself on being incredibly rich and believes his taste is the be all and end all of it. This foreshadows the Control Freak tendencies of the Man Upstairs.
The Napoleon: Technically, he's the same size as everyone else. However, he prides himself on the height he gains when wearing his platform boots, and will loudly emphasize how tall he is to any naysayers.
Not So Different: Like Emmet, he never had anyone else tell him he was special, allowing Emmet to relate to him to a degree. In the end, Emmet convinces him he is special, talking him into pulling a Heel-Face Turn and undo his freezing of the world.
The Perfectionist: He firmly believes that everything that's built should be made under strict instructions, going so far as to freeze the world to ensure this perceived perfection is preserved. At one point he even claims that all he wants is utmost perfection.
President Evil: Who rules the entire world. However, his "President" title is a cover for his true evil personality.
Rousseau Was Right: After Emmet's "You don't have to be the bad guy" speech taking full effect.
Seinfeldian Conversation: Has one with himself on the impracticality of Emmet's double-decker couch. The fact that he asks things like "What if the guy in the top middle has to go to the bathroom?" and "Who'd want to sit on the bottom? What, do you try to watch TV through everyone's dangling legs?" is one of the first signs that he and Emmet are Not So Different.
Villain Has a Point: He might be running a conformist dystopia and plans to destroy the world, but Lord Business has built a stable civilization. In contrast, the Master Builders are so individualistic they have serious trouble working together.
Villain with Good Publicity: The general public, including Emmet at the start of the movie, see him as a pretty nice guy. It helps that he doesn't publicly go by "Lord" Business until the film's climax.
Visionary Villain: He genuinely wants to create a "perfect world" full of neat and well crafted things... Too bad his plan to achieve that goal involves freezing the world for all eternity.
Aroused by Their Voice: G-Rated version. In the "Behind the Bricks" special, he mentions that Morgan Freeman (his voice actor) could read a telephone book and make it sound interesting. He does just that, and the boom-mike guy next to him looks like he's in complete bliss.
Badass: He takes down an entire army of robots with only an improvised walker.
Mentor Archetype: He serves as this for Emmet as he helps him learn the skills needed to become a Master Builder. He turns out to have shades of a Trickster Mentor when he confesses he made up the prophecy of the Special to retroactively fulfill that very prophecy. Unfortunately, this also comes with Mentor Occupational Hazard.
Mystical White Hair: The white hair is probably because of his age, but he's a very powerful wizard/master builder.
The Obi-Wan: To Emmet, whom he helps develop the skills needed to become a Master Builder on the fly. He later has an Obi-Wan Moment in which he confesses he made up the prophecy of the Special as he dies, retroactively turning Emmet into the Special as part of a Secret Test of Character. There are some very strong parallels between the character of Obi-Wan and Vitruvius. Virtruvius is a wise leader of a group with special talents and takes on an apprentice. He is struck down by the LEGO-world counterpart of the protagonist's father, and returns as a spirit advisor and reveals a secret he had been keeping from the hero.
One-Man Army: Despite being blind, he can take on a hundred robotic Mooks at once using more or less a walker.
A-Team Firing: This version of the Dark Knight is a pretty lousy shot with his batarangs in one scene.
Aloof Ally: He hates having his "every man for himself" approach to heroism shot down so much that he groans for a solid three seconds before helping his friends.
Badbutt: Not only because he's in a kids' movie but also because he really isn't that tough and skilled. He's essentially a G-rated parody of Frank Miller's Goddamn Batman, which he tries to be like but doesn't quite make it. See Pre Ass Kicking One Liner for a good example.
Broken Pedestal: Emmet is honored to meet him at first, but is severely put off by his Bastard Boyfriend tendencies. It doesn't last too long as Batman's biggest Jerkass move is revealed as a ploy to get everyone out of trouble.
But He Sounds Handsome: Part of the plan to infiltrate Lord Business' office is for Bruce Wayne to show up and stall him. Batman tries to pretend that's not him.
Expressive Mask: A subversion. The cowl piece on the minifigure head doesn't change its shape, being LEGO, but the white-on-black eyes on his minifigure head do change, giving the illusion of the entire mask emoting.
It's All About Me: Is incredibly self-centered, which makes it convincing of him to abandon everyone in the middle of the ocean to have some alone time, only to subvert it a minute later when he pops back with the equipment he and his friends need to escape.
Lighter and Softer: Despite being hailed as Darker and Edgier by Wyldstyle (and himself), he's much sillier than most depictions of him. Again, probably because an 8-year-old boy came up with his personality.
Metal Head: REALLY loves his surround sound systems and subwoofers, as well as composing death metal.
Affably Evil: Good Cop can be nice. On one hand, he doesn't do anything to stop Emmet almost being melted by torture laser. On the other hand, he is strong-willed enough to stop Bad Cop from freezing his own parents.
Badass: Evil or not, Bad Cop is damn awesome in combat.
Even Evil Has Loved Ones: Bad Cop, while being more ruthless than Good Cop, still loves his family dearly. You can see how heartbroken he looks when he has to freeze them. At one point, he even addresses them as "Mummy and Daddy".
If You're So Evil, Eat This Kitten: In order to prove his loyalty after failing to reclaim Emmet and the Piece, Lord Business orders him to fire the Kragle at his own parents. The cop can't bring himself to do it, so Lord Business erases his good side, allowing Bad Cop to freeze them unfettered.
Improbable Aiming Skills: During one of his chair tantrums, he manages to hit a cop running away far off in the distance with the chair he just kicked.
Literal Split Personality: Not entirely split, but Good Cop and Bad Cop are distinct faces on the same head. Lord Business enforces a Split Personality Takeover when he erases Good Cop's face, giving Bad Cop complete control; however, Bad Cop restores Good Cop in the finale by crudely redrawing Good Cop's face.
Mistreatment-Induced Betrayal: After Lord Business betrays him for no real reason other than "it's just businessnote Lord Business", Bad Cop restores his previously erased Good Cop self and helps the heroes escape.
Morality Chain: Good Cop may not be as assertive as Bad Cop, but he does rein in Bad Cop's sadism to some extent. Good Cop's presence stops Bad Cop from using the Kragle on his parents, but once Good Cop's gone, Bad Cop does it without question.
Punch Clock Villain: He only does what he does because it's his job, and is quite caring of his parents. This gives Lord Business to keep him on the job permanently.
Rabid Cop: Bad Cop demonstrates these tendencies as he screams at Emmet throughout his interrogation, repeatedly clobbers his robot henchmen with chairs, and relentlessly pursues the Master Builders across the LEGO universe.
Real Men Wear Pink: When about to leave with Lord Business, he's seen carrying a pink suitcase with stickers.
Running Gag: Bad Cop always throws or kicks around a chair whenever he gets angry. He even brings the chair with him during chases.
Changed My Mind, Kid: He's one of the first Master Builders to leave when he sees how unqualified Emmet is as a leader, but comes back to help after the heroes evade Bad Cop's detection in Emmet's double-decker couch, realizing that Emmet's ideas are dumb enough to work.
Jade-Colored Glasses: He once led the initial charge against Lord Business, but the overwhelming defeat he and his crew suffered not only resulted in Metal Beard losing his body, but also caused him to believe that any further attack on Business's forces, Special or no, would be a lost cause. Emmet's naivete reinforces his cynicism as much as it inspires him.
Jerk with a Heart of Gold: Metalbeard is a cynic and a bitter man, but most of this is down to the loss of several Master Builders in the past, and he ultimately comes back to help the heroes in spite of Emmet's naivete.
Percussive Maintenance: Inverted. After going through all the effort to build his spaceships, only for the idea to be shot down, he can instantly disassemble the entire thing just by tapping it with his foot.
Playful Hacker: He's a wiz at computers, at least from the 1980s. Any newer technology is a bit beyond him.
Running Gag: All of his attempts to build a spaceship get shot down until near the end of the film, where he's surprised that nobody speaks up to veto his spaceship plan.
Cloudcuckoolander: In a really punny way; being from Cloud Cuckooland she technically is one, even having her head (and the majority of her body) in one for a while. However, she's quite coherent and aware of her surroundings, which makes it absolutely heartbreaking to see her sad when her home is destroyed.
For one, Uni-Kitty has no romantic relationship with any male character at all, a serious plus for a female character in a kids movie. She loses everything, but manages to stay grounded and positive. [...] She is decidedly ultra-feminine, but she is a valued and strong part of the team.
Hidden Depths: Unikitty appears to be a happy-go-lucky cutie, but it's made clear early on that she has some anger issues to resolve. She finally drops it in the finale and goes berserk on Lord Business' Micromanagers.
Hulking Out: The anger she tries to repress throughout the movie bursts forth after she basically decides "ah screw it" during the climax... and many Micro-Managers were deconstructed afterwards.
Is This What Anger Feels Like?: Anger is a very foreign concept to the people of Cloud Cuckoo Land, so much so that she can only describe it as "the opposite of happiness".
Non-Standard Character Design: She's the only main character who isn't a LEGO minifig, instead being a cat/unicorn made entirely of bricks, with her face being a decal on the brick, and unlike all the other characters her parts change dramatically as she prances around, or sits, or goes berserk.
Paper-Thin Disguise: The Master Builders draw glasses, a tie, and various financial symbols on her so she can blend in in the Octan Tower board room. She still acts just as energetic and excitable, merely peppering her speech with words like "business" and "numbers", yet the robot board members seem completely taken in by the ruse.
The Pollyanna: She tries to be this after Cloud Cuckoo Land is destroyed, constantly needing to remind herself to "stay positive". It doesn't last.
Rage Breaking Point: She does herself to push down any semblance of anger she has throughout the movie, but when Emmet is attacked by the Micromanagers, she finally decides to drop the "positive" act and goes on a rampage.
Batman: I left the weird cat-thing to distract the robots. *cut to the main meeting room* Uni-Kitty: *attempting to distract the Business-Bots* Business, business, business, numbers, numbers, numbers! Is this working? Business-Bot: Yes. Uni-Kitty: Yaaay!
A House Divided: The drawback to being able to create for themselves is their inability to work together since they're all only knowledgeable to their own niche LEGO sets. Emmet's Heroic Sacrifice inspires them to band together.
Dead Star Walking: Several Master Builders were involved in a raid on Lord Business' base, including The Flash. They all died (or captured and placed in the Think Tank, this is never made clear) except for Metalbeard, who was badly wounded.
Screw This, I'm Outta Here!: Their general response to learning Emmet is the least qualified Special they could have possibly hoped for is to run away. Lord Business' arrival only hastens their resolve. Subverted later when the all return after Lucy's speech about Emmet's sacrifice.
Casting Gag: The fact that Cobie Smulders voices her can be considered a Discontinuity Nod as well, since she was, at one point, picked by Joss Whedon to play the character in his script for the canceled film.
Mythology Gag: There is focus on her being handcuffed and taken away by Lord Business's forces. In Golden Age Wonder Woman comics, having her hands tied nullified her powers.
Didn't See That Coming: Has his fellow basketball players build a catapult to which he plans to launch a basketball at Lord Business invading ships...and it fails because the ships were sealed with Kragle.
Deus ex Machina: Of a sort. His intervention allows Emmet to return to and save the LEGO universe.
Flat "What.": His response when his father suggest they let Finn's sister play with the LEGOs as well. Considering that Duplo blocks (larger, blockier, er, blocks made by LEGO for very young children) invade Bricksburg and state their intention to destroy, this is seen as a very bad thing (at least from Finn's point of view).
God: one of two from the Lego peoples' point of view
Finn's unnamed father, on whom Lord Business is based.
Adopt the Dog: He decides to let his son and daughter play with his own LEGO collection, realizing that it's more important for them to expand their minds creatively than to have all the LEGO stuck in place.
Archnemesis Dad/Flanderization: He's strict and likes his LEGO to be separate and untampered with, which is exaggerated in Lord Business' evilness and his desire to permanently freeze everything in the universe in place.
Anti-Villain: He simply wants his toys to be left organized, though he still wants his son to have fun (albeit with a much smaller set of LEGO).
Bigger Bad: He's the inspiration for Finn's plot about Lord Business wanting to glue together the universe, but isn't directly involved in it until the climax.
Chekhov's Gunman: Vitruvius mentioned him when he and Wyldstyle entered Emmet's mind.
Control Freak: He hates that his son messes with his orderly LEGO sets, and decides to use Krazy Glue to glue the pieces together to prevent further tampering. It's such a part of his character in fact that Finn unintentionally gives Lord Business the exact same line in his playtime that his dad will use later in the film:
Lord Business/The Man Upstairs: I have a way of keeping things exactly the way I want them! ...permanently.
Corrupt Corporate Executive: Invoked in-universe, but downplayed in the real world; while Finn's father definitely has a white collar job, which translated to Lord Business being an evil executive, the real guy isn't seen to be corrupt or even an executive.
God Is Evil: The mini-figures call him "The Man Upstairs", with a similar reverence to him as humans would to God. However, he's a much less benevolent "deity" than his son, wanting order to his LEGO sets and stifling creativity. He ceases being "evil" at the end, though, just like villain Lord Business.
Humans Are Cthulhu: His "relics" are described in horrifying terms (by the standards of a kid's movie / kid's playtime, that is), as is Emmet's vision of his hand. There's a definite Lovecraftian thing going on with the relationship between him and the LEGO figures.
Hypocrisy: The Man Upstairs is practically hypocrisy incarnate.
Moral Myopia: He hates it when Finn dismantles his sets, yet when he dismantles his son's creations it's justified because it's orderly.
Parental Hypocrisy: Judging from the presence and worn out condition of Benny, the Man Upstairs has been collecting LEGO since he himself was a boy and played with it an awful lot (enough to have dismantled Benny's original spaceship and forgotten how to reassemble it).
Selective Obliviousness: He expects his son to respect the instructions, yet when his son tells him that all his LEGO sets are for children under 14, he says that it's "just a suggestion" and that "they have to put that on there".
Jerkass: Starts off as this, going as far to ripping his son's creations apart, and gluing certain pieces so that his son would not use them.
Jerkass Gods: Those creations were (unbeknownst to him) sentient entities who viewed him as a God.
Man Child: He tries to defy this, insisting that keeping his sets orderly is the "adult" way to use them. His son protests, pointing out that they're still toys and the instruction boxes say they're for ages 8-14. Ultimately his attempts to try to seem mature just further display his immaturity until the end when he's able to reconnect to his inner child.
Obliviously Evil: He's just having an argument with his son about the proper way of handling their toys. Down there, a universe is being destroyed because of it.
Goo Goo Godlike: With her father's permission to also play with the LEGO sets and the invasion of the Duplo Aliens (whom she deploys and speaks through), it's very likely she falls under this trope.
Sequel Hook: Finn's dad decides that not only is his son allowed to play with his sets now, but his daughter is too. Cue a sparkly spaceship (shaped like a LEGO flower piece) arriving over Brickburg, deploying hostile aliens made of Duplo blocks.
The Voice: We don't see her, but we hear her voice speaking as the voice of the aliens.
Beamed down from a disco ball of sorts, the Duplo aliens are the creations of Finn's sister, and they don't come in peace.
Eldritch Abomination: Played with. Duplo doesn't mesh with other LEGO sets and the creatures are aliens who don't look like anything that has ever existed. Unlike the all-star cast who have distinct adult voices, the Duplo aliens have toddler-voices. They're as out-of-place as you can get without terrifying the kids.