Modified souls were created through Project Spearhead (尖兵計画 (スピアヘッド), Supiaheddo; Japanese for "Vanguard Plan"), in an attempt to even the gap between Shinigami and Hollows, as Hollows generally outnumber Shinigami. The Mod-Souls created varied in their abilities and can be defined by different types. For example, one Mod-Soul may be able to run many times faster than a regular Human while another may be many times stronger than normal. Kon, the Mod-Soul accidentally ending up in Ichigo's possession, has enhanced leg-strength, which makes him a Underpod (部下強化型 (アンダーポッド, Andāpoddo; Japanese for "Lower Part-Strengthened Form") type of Mod-Soul.
The Mod-Souls, 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 Mod-Souls 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 Gikongan that contained normal artificial souls and shipped to Kisuke Urahara's shop, where Rukia Kuchiki 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.
Known Mod Souls
|Kon||Enhanced Leg Strength||Active|
- Bleach manga; Chapter 15, page 9
- Bleach manga; Chapter 15, page 9-11
|Anime Mod-Souls||Kagerōza Inaba • Kai • Nozomi Kujō • Kurōdo • Noba • Ririn • Ōko Yushima (Mod Soul)|
|Related Articles||Modified Soul • Gikon • Reigai • Ōko Yushima (Original)|
|Combat||Zanjutsu • Hohō • Kidō • Hakuda|
|Abilities||Zanpakutō • Reiryoku • Reiatsu • Reiraku • Konsō • Shunkō|
|Government||Soul King • Central 46|
|Nobility||Kuchiki Clan • Shihōin Clan • Noble Houses • Kasumiōji Clan • Ise Clan • Tsunayashiro Clan • Formerly: Shiba Clan • Ryōdoji Family • Dark Ones|
|Military||Gotei 13 • Onmitsukidō • Kidō Corps • Royal Guard • Gatekeepers|
|Institutions||Seireitei Communication • Shinigami Research and Development Institute • Shin'ō Academy|
|Recreational||Shinigami Women's Association • Shinigami Men's Association • Tea Ceremony Club • Ikebana Club • Calligraphy Club|
|Locations||Soul Society • Seireitei • Central 46 Compound • Nest of Maggots • Sōkyoku Hill • Gin Tonbo • Kuchiki Manor • Central Great Underground Prison|
|Items||Jigokuchō • Gigai • Reigai • Gikon • Modified Soul • Denreishinki • Ōken • Gokon Tekkō|