Chappy dispenser. The most popular among female Shinigami
Artificial souls (義魂丸, gikongan), as the name suggests, are souls designed by Shinigami scientists to separate a shinigami's spirit from a gigai, should they be inhabiting one, or to evict stubborn spirits from their corpses if necessary. When ingested, it forces the soul out of the body and takes control of it, operating in a pre-programmed manner until removed by the shinigami. It is commonly called Soul Candy, as the Shinigami Women's Association complained that the name gikongan wasn't cute and had it changed.[1] To fit with the more informal name, Soul Candy is contained in PEZ-like dispensers with cartoon characters on top. The souls themselves apparently have personalities to match the cartoon character in question; for example, Rukia Kuchiki's favorite version, Chappy the Rabbit, is a hyperactive character that tries to restrain Ichigo when given control of Rukia's gigai and even speaks in a cutesy baby talk manner. While Captain Tōshirō advanced squad is in the real world, their artificial souls were specially designed by Lieutenant Yachiru Kusajishi.
Modified souls
Modified soul (改造魂魄, kaizō konpaku)) more commonly refered as Modsoul 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.[2] Kon , the modsoul accidentally ending up in Ichigo's possession, has enhanced leg-strength. The modsouls are condensed into tiny, candy-like orbs and placed into corpses to achieve their function as soldiers to combat hollows. They are also more independent to fit with their purpose.
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 use as weapons against the hollows. Kon was somehow mixed into a batch of regular artificial souls (Soul Candy) 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 creted 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.