- "Impossible...Unthinkable...How could I... I cannot be beaten by lesser beings such as these...And I had just been reborn into this world...I cannot...I must not...""
- ― The Shadow Queen's final words before her defeat.
The Shadow Queen is the true main antagonist and final boss of Paper Mario: The Thousand-Year Door. She is an ancient, 1,000 year-old demon who once threw the world into the depths of terror. Years ago, four heroes rose up against her, and used the power of the Crystal Stars to seal her behind the Thousand-Year Door. Many years later, Sir Grodus, the leader of the Secret Society of X-Nauts, planned to obtain the Crystal Stars so that they could resurrect her, and use her powers to conquer the world.
She is the fifth and final boss of Chapter 8 and is overall the seventeenth and final boss of the game.
Paper Mario: The Thousand-Year Door
After Grodus released the Shadow Queen, he presented her with Peach, which was needed as a vessel for her spirit. After the Shadow Queen possessed Peach, Grodus orders her to destroy Mario and his allies. However, the Shadow Queen refuses, and instead questions the fact that Grodus was giving her orders. Despite the fact that she displayed that she isn't so easily controlled, Grodus still angrily demanded her to do as he says, threatening to "send her back into the depths". Insulted by the fact that Grodus tried to make her a slave to his whim, she blasted him with a lightning blast, breaking him into pieces in the process, leaving only his mechanical head. The Shadow Queen then tells him that "[he] would do well to learn [his] place", stating that she takes orders from no one. After the second strike to Grodus' head, the Shadow Sirens (replacing Doopliss) appeared. As it turns out, Beldam was the true mastermind behind the events that took place in the game. She revealed that she was the one who spread the rumor of an ancient treasure that rested behind the Thousand-Year Door, in hopes that someone would find the seven Crystals Stars and break the seal. She had also manipulated Grodus and his organization by telling him a lie, stating that the Shadow Queen would obey the orders of whoever awakened her.
After the Shadow Queen congratulates the Shadow Sirens for their work, she offers Mario and company a chance to join her. They, of course, refuse the offer, and engage her in combat. Mario and his allies won the first round, but when round two began, the Shadow Queen revealed her true form, becoming invincible in the process. She was completely immune to the attacks of Mario and his party. During this time, she offers them another chance to join her, stating that she'll forgive them for their resistance. As soon as they refuse again, the seven Crystal Stars appear, and scatter across the world, returning to the areas that they came from, in order for everyone to send their wishes and positive energy to give Mario and company the power they needed to defeat the Shadow Queen, as well as breaking her invincibility barrier. This also caused Peach to temporarily break free from the Shadow Queen's control, and decided to refill the HP, FP, and SP of Mario and his allies. As soon as the third round began, the Shadow Queen was no longer invulnerable, and their attacks actually began to inflict damage on her. After a long, tough battle, the Shadow Queen was eventually defeated, and Princess Peach was returned to her normal self.
As being the final boss of the game, the Shadow Queen possess numerous of moves that is damaging.
- Lightning Strike: In a blink of an eye, the Shadow Queen unleashes a bolt of electricity. She does this move in both of her forms.
- Stats Raise: The Shadow Queen will either raise her Attack or Defense by 3 for a few turns.
- Stats Mist: The Shadow Queen blows a mist that varies in color. The color depends on the status effect which could be dizzy or poison. The Feeling Fine badge is an effective way to avoid any status effects.
- Hand Leech: The Shadow Queen will use one of her hands to drain Mario or his partner's HP and give the HP to herself.
- Hand Slam: The Shadow Queen will use one of her hands to slam down at Mario or his partners.
- Multiple Hand Charge: The Shadow Queen will use her army of small hands to charge at both Mario and his partners inflicting damage.
- Multiple Hand Attack: The Shadow Queen will use her army of small hands to grab either Mario or his partner and drag them under the stage dealing multiple damage.
- Dark Wave: The Shadow Queen's strongest attack. First, she will raise her attack power by 7 and then use her next turn to unleash the Dark Wave dealing massive damage. This attack is infamous for being tough to guard against and is recommended to use Vivian's Veil technique to avoid major damage.
- Shadow Wave: Should this attack be used while the Shadow Queen has raised her status, then the attack is called the Shadow Wave, which does 17 points of damage.
Shadow Queen's Awakening
World of Darkness
Shadow Queen's True Power
The Final Battle
- The Shadow Queen is one of the strongest and most powerful villains in the Paper Mario series, and one of the strongest and most powerful villains in the entire Super Mario Bros. series.
- The Shadow Queen is quite different in comparison to the previous villains, seeing as she is the first and (so far) only villain in the Paper Mario series to be both a female antagonist and fought underground.
- During the battle with the Shadow Queen, the in-battle slot machine is fixed to land on all Shine Sprites, which heals Mario and all of his partners, refills his Flower Points and Star Power, and fills the audience.
- The player accepting the Shadow Queen's offer to join her will trigger a Game Over.
- While the Shadow Queen has 150 HP, she must be depleted 60 of her HP to advance to the second phase; if that's counted as part of her HP, then the Shadow Queen has 210 HP, which is ten HP more then Bonetail, who has 200 HP.
- This is the second instance in which one of the main characters ends up getting possessed by the final boss. This originally happened in Mario & Luigi: Superstar Saga, when Bowser was possessed by Cackletta's ghost and became Bowletta.
- The Shadow Queen is the second female antagonist of a Mario RPG game. The first was Cackletta from Mario and Luigi: Superstar Saga and the third are Princess Shroob and Elder Princess Shroob from Mario and Luigi: Partners in Time.
- The Shadow Queen can also be seen as a doll at Fort Francis in the game Super Paper Mario.
- The Shadow Queen seems to have the tallest crown out of all of the characters with crowns.