PLAYER INFORMATIONNAME: Quinn
ARE YOU 18 OR OLDER?: Yes
CONTACT: Quiverby on Plurk, e-mail angelicphoenix at gmail
CURRENT CHARACTERS:Nope
CHARACTER INFORMATIONNAME: Margaret
CANON: Persona 4 (PS2 version, not Golden, 100% Compendium run.)
CANON POINT: Post-True End
CHARACTER AGE: Margaret's age is unknown. She seems to be in her mid to late twenties, however she is almost certainly older, due to her status as Velvet Room Attendant. She is certainly no longer a child or teenager.
HISTORY: Found here at the Persona WikiA few notes: As Persona 4 is a video game, there are multiple choices that the player can make. In Margaret's world, her Protagonist, named Souji Seta, summoned all of the Personas available, and the Compendium that she has with her in-game has every Persona possible in the PS2 version of her game.
PERSONALITY: Margaret, at first glance, seems to be a well-polished, suave, slightly-sensual woman of the world. However, this covers up a very limited knowledge of the world. As she has, for her entire life lived in the Velvet Room, a liminal space between worlds, she has very little knowledge of the practicalities of life. This is seen in some of the questions she asks the Protagonist and comments she makes while he is showing her Persona in her social link. She states that she does not know her place in the world, and when she finds that, she will be able to move on from the Room. However, she does not seem to wish to do so, unlike her sister Elizabeth, who left to find her own answers.
Her speech patterns are very formal, and her voice is gentle and a bit sensual. She speaks to the Protagonist respectfully, and takes her position as assistant to Igor in the Velvet Room very seriously. Everything she does compliments him, and assists the Protagonist. At no point does she question or resent her position, in fact, she seems to enjoy the moments where she can explain something, or provide assistance to the Protagonist. She, through her Social Link, tells the Protagonist a number of stories about various Persona, and certainly enjoys the telling of them. She does not show much of her inner feelings or inner thoughts, cloaking all of this in her vocation as an Attendant. This leads to a bit of internal conflict, as she does not know much of who she actually is in the grand scheme of things. However, with her passion for knowledge, shown in her in-depth stories, she wishes to know more about the outside world, and did develop a strong connection to her Protagonist.
Even though she is an extremely poised woman, she has a playful side as well, laughing along with the stories she tells, joking about her past in the room, and extremely subtly making fun of her master Igor. She teases the Protagonist about his abilities, all the while seemingly longing for them herself. When the Protagonist is leaving Inaba, she confesses to a 'wicked desire' to kiss him, and does so, amused at her own actions. Her playful streak comes out even more with her siblings, at one point sending her brother Theodore out for an excessive number of cans of soda.
She has a somewhat complicated relationship with her siblings, teasing Theodore and ordering him around, but still obviously caring for him. It is also clear that she knows more about the world than Theodore does, and is quite gleeful to torment him with this fact. With Elizabeth, her sister, things are more complicated. Elizabeth leaves the Velvet Room before the events of P4 to search for a way to save her Guest. Margaret is very conflicted about this, not understanding why Elizabeth would leave, and disapproving of the reason why. She does not really understand where this bond her sister has made is coming from, nor does she think it is appropriate for her to have made in the first place. However, she does speak fondly of her childhood with her sister, so under all of the confusion and prickle, she does care.
ABILITIES: Margaret, by her own words, is a Guardian of Power. She has the ability, through the Compendium book she holds, to summon and fuse Personas, manifestations of the wielder's soul. When her Guest finds a Persona card (symbolized by one of the Major Arcana of Tarot) in battle, it is registered in her Compendium, and she can call it up again (for a price!). She also has the ability to take two or more Persona and fuse them into new Persona. In addition, she is able to summon and use multiple Persona herself in battle. In theory, she can use any Persona in her Compendium, however, in the game, she favors a few, as seen on the wiki
here. Her Persona have the highest damage spells possible, even stronger than the Protagonist has access to, as well as strong defenses and resistances. In addition, she is well-versed in the mythology behind each of the figures the Persona represent, and is an extremely good reader of Tarot. She uses a magically-manifested deck that is summoned from her Compendium.
SINS & VIRTUES: Lust – The strongest Sin that Margaret indulges in is her lust, not for sexual gratification, but for power. She is enticed by power and those who hold it, and she will do whatever she can to see or taste that power.
Diligence – As a Velvet Room Attendant, her entire life is centered around providing support to Igor, her master, and the Guests in the Velvet Room. She will do whatever it takes to assist her Guests without complaint.
Pride – Margaret is quite powerful, both through her knowledge of Persona and Tarot, and her ability to pull them from the Compendium. She is quite proud of this fact, calling herself the Guardian of Power, and at least once in every game she appears in, challenging the Protagonist to fight her.
Temperance – She is very balanced in everything she does, as well as extremely restrained. She rarely shows much emotion, and even when she does, it is not harsh at all.
Envy - In her interactions with the Protagonist, it is clear that Margaret wants to have the depth of soul, that he has. She can summon Persona with her book, however, he can do it just with his soul.
SAMPLESTest Drive ThreadAnother thread. 
