Alexander Ephiram Karsath is the main protagonist of The Interference and its sequels. He is a teenage boy whose heart accidentally connects with the universe of the Kingdom Hearts series late one night. Alex is the wielder of a magical weapon called the Lockshield, and also harbors a number of other powerful abilities and gear.


Alex lived in Portland, Oregon his entire life, with his sister Erica, his mother Wendi and his father Peter. Before middle school, Alex was not a very popular student, concentrating more on his studies. Peter was a computer repair technician, and this interest rubbed off on Alex as he grew up, leading him to become very interested in computers and video games.

However, Peter became more interested in women outside of his marriage, and he and Wendi divorced when Alex was only ten years old. Peter stopped living with the rest of the family, and Wendi, Alex, and Erica moved to an apartment complex. Alex became the man of the house and started to take on a lot of responsibility, and when he reached middle school he worked harder to gain popularity, earning himself a large group of friends.

However, Erica's degrading personality began to put a toll on Alex as she forced many of her chores on him. Alex was unable to complain as his mother had started a night shift, and once high school started the combination of work weighed Alex down. Any moment out of the house became an escape, but not as much as video games, where Alex felt he had much more control over the events surrounding him.

Eventually, the longing to be a part of that world grew, and on the first of August, two weeks before his fifteenth birthday, his heart connected with the world of Kingdom Hearts.


Alex is a sharp person and highly prefers to be, not the most intelligent, but the most knowledgeable person in situations. His nature as a player and his research on the games he interferes with tends to make him the most authoritarian member in a party and the most important resource for plot-related information.

Unfortunately for other characters, Alexander has a requirement for a certain level of control over situations, and interferences offer him situations where he does actually hold that control. The specific knowledge that he has regarding events and character weaknesses allows him to maintain a controlling position over the progress of a journey. Luckily, his use of information is not random - he does not use it to break away from the plot, where he would lose track and control of the story. Alex prefers to know where his cards lie, and that happens best when he follows the rails.

His attitude to game plots as things to control and challenges to overcome spills over to characters. He is just barely made aware of such problems when faced with guilt for them. For example, he shows surprise when Sora thanks to him for saving Kairi, recognizing that he didn't save her because he wanted to, but simply as an attempt to rebel against the story in which she was kidnapped.


Alex starts off as a normal human being with short brown hair and hazel eyes. His hair is flat during the first six chapters of The Interference but becomes spiked when Flora, Fauna, and Merryweather transform his clothing. During the first three stories, he is described as being a head taller than Erica. In The Interference IV, Alex gains scars over his body from both the Shock Cuffs and sparring with Azelas. After the Dark Eco treatments, Alex's genetic structure is altered, and he grows long ears.

Alex's outfit changes multiple times over his travels as an Interference. When the three fairies transform Alex's clothing into adventuring clothes, he is given a dark red jacket over a black under-shirt, dark green baggy slacks with large side pockets, dark brown boots, and gray fingerless gloves. During The Interference II he is also given one of Roy Mustang's spare pyrotex gloves, which he wears under the fingerless glove on his left hand.

However, at the beginning of The Interference IV, Alex's adventuring clothes are confiscated by the Krimzon Guard, and he is left with a basic Haven prison uniform. He is also given two Shock Cuffs. Some months later, after being inducted into the Guard due to good behavior, he dons a custom uniform consisting of a black jacket, green shirt, red shoulder guards marked with the KG logo, jeans, and black sneakers. This lasts until the Dark Eco treatments.

Jenny210 TI4 Karsath

Art by Jenny210 from 2007 of Alex created for Dark Renegade.

Once Jak II's main events are set in motion another year later, Yen Sid gifts Alexander with a replacement costume. This consists of a black short-sleeved jacket over a dark blue long-sleeved turtleneck; the jacket has a white Kingdom Hearts crown symbol on the front left shoulder area and a white Kingdom Hearts heart symbol on the back left shoulder area. He also wears black pants and black steel-toed boots, with a violet sash connected at the front and to the left side of his person by a watch with the Chrono Trigger symbol embossed in it. He wears two different gloves: his right-hand glove is black and has the thumb, index, and middle fingers cut off, and his left-hand glove is reminiscent of the glove given to him by Mustang, only this one has the pinky and ring fingers cut off.

Powers and WeaponsEdit

Alex's primary weapon is the Lockshield, which was created specifically for him by The World, although it eventually falls into other peoples' hands as well. Its basic form and Alex's default is the Heartless Seal, but there are multiple designs he can choose from. Each one unlocks a certain powerset which Alex is limited to while wielding. Alex has wielded every known design of the Lockshield.

During The Interference II, Alex is sent to the gate, where he inadvertently trades much of his heart's light for knowledge of alchemy. This triggers the ability to create an alchemic circle without drawing one. Alex limits this technique to imitating Edward while in battle (once imitating Scar's destruction alchemy technique) but has been known to use it in emergencies outside of battle. At the Spire of Lebis, he is also handed one of Mustang's pyrotex ignition gloves; this is destroyed in The Interference IV when Alex's accuracy is extremely decreased.

In The Interference IV, Alex also has a Morph Gun, which has four modifications: Scatter Gun (shotgun), Blaster (semi-automatic rifle), Vulcan Fury (heavy machine gun), and Peace Maker (rocket launcher). Each modification requires a different kind of ammunition. Alex inherits the Morph Gun from Azelas via Sig.

Alex's enchanted clothing allows Alex extra durability and stamina, enabling him to travel for long distances and time periods without food or sleep, although he still requires those things more frequently than the game characters do. Included with the clothing are Drive Forms which are gradually added to the first adventure; Alex shares all the same Drive Forms as Sora does, merely collecting them in a slightly different order. However, unlike Sora, Alex's Anti-Form seems to be an innate part of him. It is made worse after the Dark Eco treatments, where it becomes his only usable Drive Form.