Vivian is a major character in Paper Mario: The Thousand-Year Door. Vivian originally worked as a member of the villainous Shadow Sirens alongside her sisters, Beldam and Marilyn. Later, Vivian defects from the Shadow Sirens and joins Mario as his fifth party member. Although she suffers from an inferiority complex, throughout the events of the video game, Vivian's character develops as she learns to respect herself.
 Paper Mario: The Thousand-Year Door
Vivian's first appearance in Paper Mario: The Thousand-Year Door is in Chapter 2, when the Shadow Sirens were sent by Sir Grodus to ambush Mario. Grodus gives the three a picture, and they go to Boggly Woods. Vivian found Flurrie's Necklace while going there. However, Beldam loses the picture and blames Vivian for it, taking away the necklace from Vivian. When Mario passes by again, it is discovered that Beldam had the picture all along, but is still angry at Vivian. They then challenge Mario to a fight. In this fight, Vivian is the middle strongest of the party and uses magic. After they are defeated, they run away, leaving behind Flurrie's Necklace. Vivian hesitates and goes back to get it, but ends up leaving.
Later on, at the Creepy Steeple, Mario fights Doopliss, a Duplighost. He steals Mario's body and identity, leaving Mario as a shadow. Meanwhile, Vivian and the Sirens have devised an 'infallible' plan. They have a weapon that will surely wipe out Mario: the Superbombomb. However, it is lost, presumably by Beldam, but it was blamed on Vivian. Vivian is sentenced to search for it while Marilyn and Beldam take a nap. When Mario returns to Twilight Town, he finds Vivian searching for the Superbombomb. Possibly because he believes it will be used to eradicate the doppleganger, Mario finds it for Vivian, but they soon find that the bomb is broken. Vivian then gets saddened, saying that she was probably "meant to be punished for life", but Mario cheers her up. Vivian then asks Mario his name, but Mario is unable to say his name however, and he tells his story to Vivian. She is shocked to hear that his name has been stolen, as such things don't often happen. Vivian decides to repay his kindness and help him get his name, identity, and body back.
When Mario and Vivian finally reach Doopliss's room in Creepy Steeple again, they battle him along with all Mario's old partners, who think Doopliss is Mario. Vivian feels like a fool upon realizing that the one she was helping was Mario, and will not help him in battle for two turns, before returning to his side because he was kinder to her than any of her siblings. After Doopliss is defeated, Mario's partners ask why he would join up with a Shadow Siren, but Mario stands up for her and Vivian joins Mario's party for good, and eventually develops a friendship with at least one of Mario's other partners, Goombella. While Vivian was one of the Shadow Sirens, she hadn't been aware of Beldam's plans to awaken the Shadow Queen, and eventually helps Mario defeat the demon and save the world.
At the very end of Mario's adventure, Beldam and Marilyn end their villainous activities and promise not to mistreat Vivian again. When Mario is preparing to leave Rogueport, Vivian is about to tell Mario that she has a crush on him, but decides otherwise, saying that she thinks he and Princess Peach will make a good couple.
 Super Paper Mario
 Super Smash Bros. Brawl
 General Information
 Powers and Abilities
Outside of battle, Vivian possesses the same ability Lady Bow has in Paper Mario, but Vivian's works in a more interesting effect, as instead of literally turning invisible, Vivian can pull Mario into their shadow, where they can hide and nothing can get them. This allows them to get past objects that move over them, and avoid sight from enemies and their attacks. Vivian possesses the strongest magic of any partner in the game.
 Attacks and Stats
At Initial Rank (-), Vivian has 15 HP. At Super Rank (*), Vivian has 20 HP. At Ultra Rank (**), Vivian has 30 HP. Vivian is one of the most versatile characters in the game.
In the Japanese version of Paper Mario: The Thousand-Year Door, Vivian was said to be a male. It is openly stated in Vivian's character description, which is roughly translated as "One of the shadow group, Vivian appears to be a girl but is really a boy." (in Japanese: 「カゲ三人組の一人だった オンナのコのようで ホントは オトコのコ」). Additionally, Goombella's Tattle reads: "That's Vivian. Of the shadow group, she's the youngest sister... er, brother." (in Japanese: 「『ビビアン』よ カゲ三人組の一人で いちばん下の妹 ・・・じゃなくて 弟ね」).
While Beldam uses the term "majotachi" (meaning a group of sorceresses) to refer to her, Marilyn and Vivian as a collective, she also calls Vivian "man". Despite this, female pronouns such as "her" and "she" are used when referring to Vivian, though this may be because it is considered proper to refer to transgender persons by the gender they identify themselves with. In addition, Goombella's letter indicates that her choice to be identified as female is accepted by her sisters as part of their efforts to be nice to her after the events of the game.
In the English version of Paper Mario: The Thousand-Year Door, all references to Vivian being male are removed. All instances where attention was drawn to Vivian's gender were also removed, such as replacing Beldam's "man" quotes with "Plug-Ugly" insults. Some translations in the PAL region maintained the Japanese version's portrayal of Vivian, such as the Spanish version. In the Italian version, on the other hand, the character is female, but it is said several times in the game that she was male before. The French version keeps the original Japanese description of Vivian being a boy who disguises as a girl.
 Names in Other Languages