Killing the Ancestors
Grand Night stood at one end of the recessed proving pit. A hole twice as deep as he was tall. About twenty of his strides long and about fifteen of them wide. A taught net was strung over the top creating a cage for him. Separating himself from the rest of the clan. He knew the cage wasn't for him though. It was for the damned that was about to be set loose. On the opposite end of the proving pit was a door. A large heavy wooden portcullis really. He could hear whatever was on the other side of its heavy reinforced boards. Repeated thuds as it tried to escape. All the while with its dreadful wailing. The think black fur stood up on his back as he heard the heavy ropes being pulled. Lifting the barrier. He clutched his shield and spear more tightly crouching into a fighting stance. This is it, he thought to himself. Time to prove I am worthy of being a part of this clan. Before the gate could even open fully, the monster within began clawing away at the dirt and pulled itself underneath. The hideous thing scrambled to what might be called it feet; other limbs flailing. It stood there for but a moment taking in its surroundings before locking eyes with Grand Night. The monster stood a full head higher than Night with five appendages. Each ending with sharp spear like points. It unsteadily kept itself upright on two of them, with a third occasionally used for balance. The remaining limbs swiping the air like independent pincers. Its emaciated form seemed to shift and cock this way and that as it sized up its prey. All of this was unsettling to say the least but the scariest part to Night was its fur. This creature looked like one of his one people. The Mistontli The shape of the skull and placement of the ears. The long limbs built for running and climbing. Its fur. Patchy discolored though it may be there was no mistake. This damned was once long ago a Mistontli. A wail brought Grand Night back to focus. His eyes narrowed and his body tensed as the creature dropped to all five limbs and dashed toward him.
Following the collapse of their previous civilization the Mistontli were scattered into clans feuding over resources and in need to defend themselves from the damned. Over time the need grew stronger. Clans got bigger. The damned started wandering further from their ruins. Every member of the clan needed to know how to fight. Over time it became a requirement in order to enter adulthood. Every adolescent must kill one of the damned.
The specifics of each ritual varies from clan to clan. Some have elaborate spectacles where a damned is capture and brought to an arena and fought one on one for the whole clan to watch. Another clan may send the prospective member out on their own to return with a trophy. Another clan may travel in a small hunting party to work together. The basics are the same. Kill a damned. Be welcomed into the tribe.
For the majority of the clans, there is no set date on when to accomplish this task. Rather, until you complete the trial, you are not a full member of the clan. Full members may start their own families, speak on matters affecting the whole clan, and may chose their own role within the group.