Modified souls (改造魂魄)- more commonly referred to as Modsouls, are artificial souls designed to enhance regular human physiology, making them capable of battling Hollows equally. Because there are far more Hollows than Shinigami, a project labeled Spearhead was implemented in order to create a modified soul, in an attempt to even the gap. For example, one modsoul may be able to run many times faster than a regular human while another may be many times stronger than normal.Kon, the modsoul accidentally ending up in Ichigo's possession, has enhanced leg-strength. The modsouls, just like regular artificial souls, are condensed into tiny, candy-like orbs. However, their originally intended purpose was to be placed into corpses to achieve their function as soldiers to combat Hollows. To fit with this purpose, they are also more independent than regular artificial souls .
The modsouls were exterminated after the experiment was halted due to ethical reasons, since they were intended to be used to reanimate human corpses to be used as weapons against Hollows. Kon was somehow mixed into a batch of regular artificial souls (Soul Candies) and shipped to Kisuke Urahara's shop, where Rukia and Ichigo obtained him and unknowingly let him loose. Despite a standing order to dispose of all modified souls, they kept Kon and placed him into the body of a lion plushie. Rukia and Ichigo use Kon to possess Ichigo's body when his soul is expelled from his body to fight as a Shinigami. Additionally, during the anime only Bount arc, Urahara created three additional modsouls (Ririn, Kurōdo and Noba) and installed them with Bount detectors. These three have been adapted to the anime series without changing the overall plot.
The Mod Souls :
Kon (コン, Kon)- Ichigo's personal mod soul at the start of the series.. His name is short for Kaizō Konpaku (改造魂魄, modified soul). Kon originally wanted the name "Kai" ("Mod" in the official English dub) because it sounded cooler, but Ichigo Kurosaki decided his name was going to be Kon for that very reason. Kon is an artificial soul (modsoul) designed to inhabit Ichigo's body when Ichigo is in his Shinigami form; when not serving that purpose, Kon usually inhabits a lion plushie.
Ririn (りりん)- Ririn, while in her gigai form, is a small girl with short blonde hair wearing a pink, fur-trimmed coat, a purple bird-shaped cape, and red boots. When not in her gigai', she inhabits an anthropomorphic bird plushie. Her special ability is the creation of illusions. She acts as the leader of the trio (herself, Noba, and Kurōdo), and has a fondness for games. She is partnered with Ichigo Kurosaki. At first she disliked Ichigo due to their conflicting personalities, but now she has grown to be very fond of him, even becoming at times extremely jealous of Rukia Kuchiki's close relationship with Ichigo. She can be petty and arrogant at times, but she shows real concern for her friends. She has stepped into harm's way more than a few times to help save Ichigo, Rukia, Kon, and others. She often looks down on Kon as inferior, which causes frequent arguments between the two.
Kurōdo (蔵人)- is a bespectacled man with a mustache and two-tone hair color (black to the right, yellow to the left). He wears a gray top hat, multi-colored suit and tie, as well as dark brown boots, giving him an appearance similar to a circus manager. His plushie body is a rabbit-esque purse. He is partnered with Orihime Inoue. He has the ability to shapeshift, and can replicate the abilities of others when he does so (although he can't replicate the power levels of said abilities). Kurōdo's plushie bodyHe is somewhat cowardly and is terrified of snakes. His longwindedness and actions often provide comic relief. He is also somewhat perverted, like Kon, or at the very least is thankful for the opportunity to be held by attractive women (being a purse helps in this regard). Rukia seems to like him because he resembles Chappy the Rabbit in his stuffed animal form.
Noba (之芭)- More commonly known as Nova. In his gigai, he appears as a handsome young man in a fur coat with a shield on his back and a zippered mask, with a slim build, red hair, and aqua eyes. His attire makes him look somewhat like a ninja. He inhabits an anthropomorphic turtle plushie in grey dress trousers and a white ruffled shirt with a red bow tie when out of his gigai, which Chad purchased specifically for him. He's very quiet, rarely speaking more than a few words (Usually only responding to a question by saying "no problem") and also rather shy with women, zipping up his hood when he wishes to show emotion while in his gigai, or pulling his head into his shirt while in his stuffed animal form. One example of this is when Rukia Kuchiki picks Noba up in his stuffed animal form and holds him close to her face, he is seen to blush at the close contact and lowers his head into his shirt, or when he works together with Rangiku Matsumoto while fighting one of the Bount having to change out of his gigai because they had to touch. He is partnered with Yasutora Sado, who is equally quiet. The two seem to get along well, since they are similarly industrious, silent and willing to fade into the background.
Noba's plushie bodyCompared to his far louder and more verbal teammates, Noba is very uncomplaining and easy to get along with. He doesn't annoy anyone else in the cast, and several humans and shinigami seem to be fond of him. He is also the most likely to get things done without comment; in one episode Renji spits coffee all over the table, and Noba cleans it up and then sugars Renji's coffee without a word.
Noba has the power to teleport himself and others to any location he's been to. He can also use his spiritual sense to teleport to the location of those with spiritual powers. Additionally, he can create wormholes to redirect ranged attacks, both physical and energy based, back at the enemy. He can also absorb fire. When he is in his plushie, his teleportation range is limited to about two meters. Despite being unusually shy, he is somewhat analytical and adept at strategic combat.
