A SoulSpirit is the incarnation of the a SoulWorker's SoulForce and takes on a form of the SoulWorker as a younger child. It appears to lend SoulWorkers more power in times of need at a cost. It represents a SoulWorker's trauma and past. A SoulSpirit is considered the SoulForce equivalent of a Shadow Walker. The spirit is generally only visible for its SoulWorker and not anybody else. Tenebris's ghost states it is potentially taking on form of Tenebris's SoulSpirit.

In the former SinWorker stories, the SoulSpirit makes its first appearance as a mysterious child who guides the SinWorker to fight the SoulDregs and leds them to Luckforce. It is separated from the SinWorker after it defends the SinWorker from Kairon. Shortly after, it was spotted by the members of Luckforce in Control Zone 46 and Miriam was sent to go search for it after hearing the reports of a lost child. Miriam is able to find the lost child but they were attacked by SoulDregs. The SinWorker arrives on scene to rescue the pair but the SoulSpirit was swallowed a by SoulDreg. After recovering the SoulSpirit, the former SinWorker ascends from a SoulForcer to a SoulWorker. It makes a second appearance in the Skies of Sorrow arc where it appears to lend the SinWorker the power to kill Catherine at a cost. The cost is currently unmentioned in the story.

It is unknown if Chii or Ephnel have SoulSpirits due to their irregular awakenings.