Erica Michelle Karsath is the younger sister of Alexander Karsath, and an antagonist featuring in The Interference II: Curse of the Crimson Elixir. She is a young girl whose heart connects with the world of the Fullmetal Alchemist series but is kidnapped by Dilan and turned into a Heartless.


Erica lived with her father, mother, and brother in a house in Portland, Oregon during her childhood years. While Alex was not a popular child, Erica was, having many friends at school and doing relatively well academically. Like her brother, their father's work in electronics interested her, but she didn't pursue her interest.

She was nine years old when her mother and father divorced, and didn't adjust very well to the changes, forcing away many of her school friends and causing a drop in the quality of her schoolwork. Her brother, meanwhile, improved in both aspects and was left a lot of responsibility when their mother started to work night shifts, leaving Erica envious.

In response, she began to neglect more and more of her work, constantly shoving her chores and homework onto Alex while not caring for the consequences. As Alex became more and more stressed and began to fight back against her (mostly emotionally, sometimes physically) she only became worse in response, and a large rift grew between the two of them.

During this time, Erica discovered another obsession, Fullmetal Alchemist, and began to absorb herself into its universe, finding special interest in the series' main character. Alex did like the series as well but began to drift away from it as Erica's obsessive nature made him disinterested. Meanwhile, Erica began collecting the merchandise and video games and is known to have completed them several times over.

During one particular playthrough, in the very early morning of her brother's fifteenth birthday, her heart connected with the game, and she vanished.


Contrasting with her older brother, Erica is very loud and immature. She lacks responsibility and a certain level of self-control, causing her to talk quite loudly about things until she is actually faced with a question. She is open about her feelings and can be extremely aggressive towards her enemies. At the very least, she does try to be a rallying leader, but she fails to have the experience and intelligence to back her up.

Erica is not hopeless, though; unlike Alex, she immediately hits upon the point to open the door with the Lockshield and Keyblade rather than with the fetch quest. Although she lacks information on the plot points specific to this version of Fullmetal Alchemist, she does remember the game better than Alex does, and Alex admits she has the plot down. It is mostly that she focuses on Edward and Alphonse's journey, which is, in general, the series' focus.

Throughout the journey, Erica becomes extremely jealous of her older brother, due to him seemingly having had a more accommodating first interference than her. She looks incredibly angry upon finding out that he is able to perform alchemy, and when fighting him attempts a fatal strike, which she keeps in mind after being alerted to it by him.

Important to note is that Erica's personality in the story may be distorted and obscured by Alex's perspective, which did not improve in her direction until The Interference III: Wings of Time.


Erica is a short girl, being referenced as being the same height as Edward Elric (making her 4'11 according to the Fullmetal Alchemist series guidebooks) and a "head shorter" than her brother (though this seems like an exaggeration). Not much is specified of her physical appearance apart from her hair, which is waist-length and golden blonde in color.

Unlike her brother and his magical clothes, she receives a change of clothing immediately upon reaching Amestris which have no particular properties other than allowing the wearer to only take damage in a 'video game' style. Her outfit is a large black trenchcoat, a red undershirt, black sweatpants and black sneakers.

After being transformed into a Heartless, Erica's hair changes color to blond with gray streaks, and her eyes become yellow. She is given a new outfit consisting of a second black trenchcoat with red lining, a black sweatshirt, black trousers and long boots

Powers and WeaponsEdit

Erica contrasts heavily to Alex in that when she created Amestris, she didn't gain any method of defending herself. She often hides behind walls in the beginning to avoid confrontations, which leaves Alex to protect her, something he does well. She eventually requests a weapon from Edward, who creates a lance for her using alchemy; various unnamed lances become her signature weapon throughout the story.

The first alchemical lance is directly handed to her by Edward in the sewers, and she uses it to become somewhat proficient in wielding them (considering she only wields it for a few hours). Presumably, it is a similar lance in design to the one Edward creates to fight the chimera. The second alchemical lance is given to her by her brother in Resembool. She uses this to spar with him, but after she tries to kill him, he takes it from her and destroys it.

After her transformation into a human Heartless, Erica is able to summon a lance on her own. It sports a Heartless emblem near the blade. This is used to fight with Alex on a few occasions.