When you create something, it may go through many renditions before settling on a final form. This is what happened to the Predecessors. They were supposed to fill the role humans do now, but they were too flawed. Too animalistic. Too chaotic. Some say they were so due to prolonged exposure to the lower planes, some claiming it was because the gods didn't understand how the material plane worked. Either way, they were an abandoned project, set to the side as humans were formed. Once the final version was completed, the gods that made the Predecessors tried to dispose of them, but the abominations were too close to their creators image. The only reasonable option was to cast them to Carceri to hide their shame.

Limited Number. Predecessors lack any way to have offspring, meaning there will always be the same quantity of them for eternity, somewhere around 57. This also implies those that live today are the same that were first made by the gods.

Planar Bound. When slain, Predecessors immediately reincarnate in a random point in Carceri, similar to how a Demon, Devil, or Celestial would in their respective lands. However, unlike the listed beings who permanently die if killed within those, slaying one within their home plane produces the same results as outside it, making the Predecessors practically immortal.

Self Imposed Duty. When the gods banished the Predecessors, they gave no reason for why they did so, leaving the first drafts to speculate, and finally come to the conclusion that they were placed in the prison plane to be guards, preventing any from leaving. And so the banished prevented any from leaving, even if they were simply visiting, in the hopes that the gods would be pleased and return them to the material plane, which they likely never will. Not all of them follow this belief though.

Twisted Form. Predecessors follow a similar design as the average human would, but with a few differences some would consider horrific. Most of their bone structure is locked, leading to them developing a limp and a hunch, their oversized left arm dragging on the ground as they walked. The jaws of Predecessors too are fused, vastly limiting their ability to communicate. They bear wings too small for their body and a thorn on the palm of their right hand, which they tend to use to stab and grab opponents. Their pale white skin clashes with their 4 red, blue, purple, and green eyes.