Sub-Personas (サブペルソナ, Sabu Perusona)? are a unique mechanic in the Q series.
Persona Q: Shadow of the LabyrinthEdit
Due to the location in which two Wild Card users are brought together, the normal power of the Wild Card is altered. No longer can the Heroes change their main Persona, however they and everyone else are able to equip a second, Sub-Persona. As Sub-Personas do not have stats or resistances, everyone's stats and resistances are determined by their main Persona. Sub-Personas do, however, grant a bonus to HP and SP, a bonus which is always granted at the start of battle, and grant the user additional skills, and through certain Passive Skills, namely Resist [Element] and Absorb [Element], can grant the user resistances not granted by their main Persona.
Just like Personas used by the Wild Card, Sub-Personas are usually classic mythological figures commonly seen in the Shin Megami Tensei series, although DLC Personas such as Kaguya Hime are exceptions.
If an equipped Sub-Persona is 6 levels or more below the character's main Persona, all skills suffer a penalty, reducing their effectiveness by 10%, with the penalty increasing with each level to a maximum of 50% at 10 levels below.