Queen Usurna

No, Trollhunter. We do not have it, but I am familiar of that which you seek. It was once in our possession, but stolen years ago.
„

~ Usurna's claim about what happened to the Eye of Gunmar.

“
From this day forward, we will unite under one troll leader. That leader is far greater than I. Greater than us all. I give you Gunmar the Black, the Skullcrusher, the Underlord of Trollmarket.
„

~ Usurna, revealing her true nature to the citizens of Trollmarket.

“
Instead of seeking the hole the traitors cower in, we should storm the surface and seize the humans' weaponry, use it against them. They have explosives that level cities, ripe for the taking.
„

~ Usurna suggests to Gunmar that they use nuclear bombs against mankind.

Queen Usurna, simply known as Usurna, is a major antagonist in the Tales of Arcadia franchise, serving as a major antagonist of the first installment Trollhunters (specifically being a minor antagonist in Part 1, one of the two secondary antagonists (alongside Dictatious Maximus Galadrigal) of Part 2 and a major antagonist in Part 3) and an unseen antagonist in the third installment Wizards.
She is the Queen of the Krubera race who was a member of the Troll Tribunal. However, she was secretly a follower of Gunmar, who she helped in taking over Trollmarket by condemning Jim in a false trial. It's eventually revealed that she traded AAARRRGGHH!!! to the Gumm-Gumms when she selected him as Gunmar's champion. She is AAARRRGGHH!!!'s archenemy.
Biography
Background
Hundreds of years ago, Usurna took over the Krubera and ruled over them as a despot, intending for them to help Gunmar take over the world. She selected Aarghaumont "AAARRRGGHH!!!" to become a general of Gunmar's Gumm-Gumm army from a young age and even other Krubera younglings to be part of his army as well, just to prove how useful they are to Gunmar.
It also turns out that the Krubera were guardians of the Eye of Gunmar, one of the three Triumbric Stones, though it was supposedly stolen by the Gumm-Gumms. However, due to her true colors, it's more likely that Usurna willingly gave the Eye to the Gumm-Gumms so that the Eclipse Blade couldn't be accessed, the only way a Trollhunter can have the means of killing Gunmar.
Trollhunters
Part 1
Usurna, having heard of AAARRRGGHH!!!'s agony, travels with many of the Krubera to Trollmarket, surprised to see that a human named Jim Lake Jr. is the next Trollhunter. Jim and Toby ask her about the Eye of Gunmar, and she claims it was stolen by the Gumm-Gumms centuries ago. Later, she assures Vendel that the only way to save AAARRRGGHH!!! is if he returns with his kind back into the Deep Caverns, to which he says that they can't get him away from Trollmarket.
The agreement is settled as both Usurna and Vendel create a PyroBlix match, in which Trollmarket wins. With that, Usurna gives AAAARRRGGHH!!! a choice between staying with his friends or coming with her. AAARRRGGHH!!! decides to go back with the rest of his kind at first, but chooses at the final moment to be with Jim and his friends.
Part 2
Usurna is revealed to be one of the members of the Troll Tribunal as she goes to Trollmarket with the rest of the Tribunal to discuss Jim entering the Darklands via the Killahead Bridge. Usurna is determined to do so, not caring about the fact it would leave Jim trapped in the Darklands. The Troll Tribunal decides to destroy the Bridge, and Usurna has her soldiers do the task. She decides that all the pieces of the Bridge be thrown into an abyss where no troll nor mortal can ever find them, by tossing them into boxes in a shipping crate ready to be dumped into the ocean. Claire and Not-Enrique are barely able to get all the pieces to the forest just in time using the Shadow Staff.
After this, Usurna stays in Trollmarket under orders from Gunmar to be a spy alongside a changeling named Krax, and get rid of the Trollhunter if he is able to get back from the Darklands. She lies that she stayed there because she doubts Vendel's judgments.
Soon after Jim escapes from the Darklands, Usurna manages to manipulate the Troll Tribunal into unfairly condemning Jim for supposedly releasing Gunmar from the Darklands, giving Jim an unfair choice: keep the Amulet of Daylight and be sentenced to the Deep, or surrender the Amulet and be exiled.
After a while, Jim decides to keep the Amulet, so he is sentenced into the Deep where no troll ever came out, but Jim is able to escape because he is a human, not a troll. As the condemnation takes place, Blinky and Claire Nuñez find evidence of Gunmar's spies working in Trollmarket and report said evidence to Vendel, who discusses with Usurna the possibility of more than one spy amongst them. To keep Vendel from warning Trollmarket about this, Usurna murders him using a Creeper Sun knife to turn him into stone and shatter his stone corpse. However, unbeknownst to her, Vendel recorded it using an Anamnesis Stone, which allowed the protagonists to discover her true colors.
After her murder of Vendel, Usurna lies to the citizens of Trollmarket that Jim was the one who murdered him and they can no longer trust the Trollhunter, thus having to reclaim the surface as their own. She then reveals her true nature as she introduces Gunmar as the Underlord of Trollmarket, showing her loyalty to him. Gunmar is then able to brainwash many of the trolls into becoming Gumm-Gumms, but Jim and his friends manage to rescue many other trolls. Subsequently, Usurna adds her own bodyguards as part of Gunmar's new army.
Part 3
Usurna continues to take orders from Gunmar but is ticked off with Dictatious Maximus Galadrigal's obsession with Morgana, believing her to be nothing but a myth. Dictatious tells Usurna about Morgana calling out to him and shows her the phonograph Morgana has spoken through to communicate with the Janus Order, only for Usurna to vandalize the phonograph by dropping it into a very deep hole, declaring it lost to the ages. Later on, as Dictatious is about to be killed by Gunmar, Usurna sadistically watches it, one of the things that cause Dictatious to soon redeem himself and warn the Trollhunters.
Eventually, Usurna makes a deal with the Qugawumps to capture Blinky and AAARRRGGHH!!!, the latter of which is brutalized by her bodyguards to set up an example, and sadistically reveals that she selected AAARRRGGHH!!! as part of Gunmar's army to give him a champion.
Hearing of this betrayal to a member of their own kind, Usurna's bodyguards redeem themselves by rescuing AAARRRGGHH!!!, who was almost tossed into a deep pit of thin mud by Usurna. They turn against Usurna, who tries to back off but trips into the mud pit. In her final moments, she demands that they help her out; when they refuse, she threatens that she'll make them pay, but finally sinks completely into the mud where she drowns.
Wizards
Although Usurna is never seen nor heard of, the result of her actions is shown as AAARRRGGHH!!! is a Gumm-Gumm in the past, although Blinky befriended him.
Personality
“
You don't care for Krubera, just yourself!
„

~ AAARRRGGHH!!! calling out Usurna for her selfish and treacherous nature after she reveals that she sold him out to Gunmar.

At first, Usurna appears to be a benevolent ruler towards her people and an ally with Vendel, concerned about AAARRRGGHH!!! slowly dying, and later, Gunmar's return from the Darklands. However, this is all a façade, as she is actually a merciless, power-hungry, and selfish tyrant who will do anything to get what she desires. She is a fanatical follower of Gunmar who cares about no one but herself, as she was the one who selected AAARRRGGHH!!! to become Gunmar's champion centuries ago. She doesn't even care about Gunmar, as while she does follow in the Skullcrusher's footsteps, she was willing to leave him trapped in the Darklands, as shown when she had the pieces of the Killahead Bridge tossed into a shipping crate about to be dumped into the ocean.
Usurna also proves to be an expert at manipulation, as she was easily able to persuade the rest of the Troll Tribunal into believing what she wants them to believe by using their fear of Gunmar against them. As a result, it made them willing to trap Jim in the Darklands so that Gunmar can't get out instead of assisting Jim in his escape, which would lead to a chain of events that ultimately caused Gunmar's escape. She is also xenophobic towards changelings and mankind alike, as she declared Jim guilty during his trial simply because he was a human and repeatedly called NotEnrique an "it" despite his protests. Also, the only reason why she was concerned with Nomura committing suicide was that she wanted to use her to free Morgana from her prison, not because she genuinely cared about Nomura.
However, one of the main traits about her is her cowardice and hypocrisy. After sentencing Jim to the Deep, she incriminated him for the murder of Vendel, when she did herself, and after Gunmar began to take control of Trollmarket, Dictatious warned Usurna about what would happen if she didn't follow up to Gunmar's standards, prompting her to seal all of the exits from Trollmarket so no one could escape. Eventually, when Dictatious is almost killed by Gunmar for lying about the visions Morgana gave him, Usurna accuses Dictatious of being a traitor, even though she is a traitor herself. Also, when her own bodyguards turned on her after realizing what she did to AAARRRGGHH!!!, she commanded them to stand back and accused them of betraying her, which shows that she refuses to take responsibility for her crimes, and instead blames it on others. Usurna spends her final moments demanding for her bodyguards to help her, and when they refuse, she panics as she threatens to make them pay before drowning to her demise.
Quotes
“
Usurna: A changeling? Here in Trollmarket?
Vendel: Yes.
Usurna: And you are certain of this?
Vendel: I have it on good authority. If Gunmar's agents are within the walls, something is afoot. We must suspend the Tribunal at once, and deal with the real threat!
Usurna: Real threat? You think there may be more than one ally of Gunmar here?
Vendel: Yes. If Gunmar has one agent within Trollmarket, who's to say there aren't others? It's time we root out this enemy at the core and end this!
Usurna: You're wrong, Vendel.
„

~ Usurna and Vendel discussing the possibility of there being more than one of Gunmar's spies in Trollmarket.

“
Usurna: There are only two agents of Gunmar within Trollmarket's walls: the Changeling… and the Changeling's master.
Vendel: What? How do you know this?
Usurna: Because… I'm the master!
[Usurna stabs Vendel's abdomen with a Creeper's Sun knife, and he groans as he drops his staff and he starts to turn to stone.]
Usurna: I'm sorry, Vendel. I was hoping you'd live long enough to see Gunmar's glorious return!
Vendel: Usurna, you cannot! They'll stop you. The Trollhunter…
Usurna: SHALL DIE! Farewell, Vendel, Elder of Trollmarket. Now is your end.
„

~ Usurna murdering Vendel by turning him into stone and shattering his corpse as she reveals her true nature.

“
Let this be a lesson. This is what happens to those who defy us!
„

~ Usurna's response to Blinky pleading her to stop her bodyguards from torturing AAARRRGGHH!!!.

“
Usurna: Why won't you fight?
AAARRRGGHH!!!: Won't fight Krubera. They are my brothers. They follow orders from traitor.
Usurna: Me? A traitor? It is you who turned your back on your kind.
[AAARRRGGHH!!! tries to hit her, but she grabs him and throws him against the wall.]
Usurna: It takes a leader to know how to survive, when to strike, and when to make sacrifices, like when I traded you to the Gumms-Gumms.
AAARRRGGHH!!!: No. Gunmar raided village. Took me away from family.
Usurna: Gunmar didn't kidnap you. You were selected. The Skullcrusher needed an army. I gave him a champion. What's the lives of a few younglings when the Krubera could rule alongside him?
„

~ Usurna remorselessly admits all the horrible things that she has done to her own people.

“
I am the Krubera!
„

~ Usurna before attempting to drown AAARRRGGHH!!!.

“
How dare you interfere! Stand down! I command you! [grunts] You betray your queen, you stupid brutes? I'll make you pay! I'll make you— [falls backward into the mud] Help me! Help me, you idiots! I will– I'll make you pay!
„

~ Usurna's last words before she drowns to her death.

Trivia
There are some foreshadowing hints that Usurna is a villain.
She gives AAARRRGGHH!!! a sadistic choice between staying with his friends and dying quicker, or coming with her and dying slower, as a slow death is painful.
She keeps calling Not-Enrique an "it" despite his protests.
She gives Jim both an unfair trial and a sadistic choice between keeping the Amulet of Daylight and being sentenced to the Deep, or surrendering the Amulet and being exiled from Trollmarket.
She convinces the Troll Tribunal to trap Jim in the Darklands by having the Killahead Bridge dumped into the ocean. Judging by this, it's likely that despite being a servant of Gunmar, she doesn't truly care for him as AAARRRGGHH!!! stated in Part 3 that she cares about nobody but herself.
She is one of the most hated characters in the franchise, alongside Colonel Kubritz.
Her name derives from the word "usurp", which is a term for seizing power by force.