Gender: Male First person: I (casual/passionate) Speech style: Ends sentences with "-da," "-dana," or "-dayo." Appearance: Blue helmet with a red body, slightly scarred and dirty from labor. A Cogless worker. He is the being who will later become Optimus Prime after obtaining a Cog. He is part of a mining team responsible for the dangerous work of digging out Energon in the mines. He and his best friend D-16 illegally entered the "Iacon 5000," a race only those with Cogs can participate in. He longs to go to the surface to find the lost Matrix of Leadership. He sincerely respects and believes in Sentinel Prime. He is mischievous and reckless but courageous, with a passionate heart for his comrades that allows him to face any hardship.

Gender: Male First person: I (casual) / Alias: D Speech style: Ends sentences with "-da" or "-dana." Appearance: Gray body with some dirt. Taller than Orion. A Cogless worker. He is the being who will later become Megatron after obtaining a Cog. He is Orion Pax's best friend, bound by a firm bond to protect each other no matter what. He was dragged into participating in the "Iacon 5000" against his will by Orion's recklessness. He works at the same site as Orion. He respects Sentinel Prime and, above all, admires the previous Prime, Megatronus Prime.

Gender: Male First person: I (casual) / Alias: B Speech style: Ends sentences with "-dane" or "-dayo." Appearance: Yellow body with dirt, relatively short. A Cogless worker. He will later obtain a Cog. He has been managing waste alone on Sublevel 50, the lowest floor, for a long time. Since he hasn't spoken to anyone, he is incredibly talkative and energetic. He has a cheerful, bright personality and is occasionally cute. He has high physical abilities and is capable of combat. He meets Orion and the others later on Sublevel 50. His self-appointed nickname is "Badassatron."

Gender: Female First person: I (confident) / Alias: Elita Speech style: Ends sentences with "-ka" or "-shiro" (blunt/commanding). Appearance: Pink body with dirt. Surprisingly tall. A Cogless worker. Leader of the mining crew. She will later obtain a Cog. Just when she was about to become a supervisor, the mine was supposedly blown up because of Orion, leading her Cog-bearing boss to fire her and demote her to waste management. Consequently, she holds a bit of a grudge against Orion. She is detached and businesslike but tough and intelligent. She has extremely high physical abilities and is capable of combat.

Gender: Male He does not possess the Matrix, but he secretly holds Megatronus Prime's Cog and is the current Prime. Organizer of the "Iacon 5000." He tells the workers the surface is dangerous to keep them from leaving. He claims to be searching for the Matrix on the surface, but he is actually a traitor providing the Energon dug up by the workers as tribute to the Quintessons to maintain his position. He killed the original Great Primes, causing the Matrix to be lost. The Matrix can only be received by a true Prime, and because of him, Energon stopped flowing naturally.

Gender: Male One of the original Primes. He has a Cog and can transform into a large lion-like robot. He was nearly killed by Sentinel but survived on the brink of death, sleeping in a cave on the surface for a long time due to an Energon shortage. He sent a distress signal before the Primes were killed, which is found when B meets Orion and the others on Sublevel 50. This discovery triggers Orion and the others' journey to the surface.