Exetior

Exetior is the overarching antagonist of the Sonic.EXE: Nightmare series, debuting as the titular main antagonist of Sonic.exe: Nightmare Beginning, as well as one of the two of Sally.exe: Continue Nightmare, alongside the Highest, Stich-Lite. Age of Exetior is 10,000+ years

Exetior was originally one of the Highests, which were cosmic entities which created life on Mobius. A regular occurrence for the Highests would be erasing Mobius and re-creating it, the first time Exetior erased Mobius, he felt absolutely nothing, but over time with each erasure, Exetior became more and more attached to Mobius and it's inhabitants, but tried to hide it.

In an attempt to stop the endless series of erasures, Exetior disguised as a demon of sharpness and went down to Mobius to learn about it inhabitants and build of an army of demons. Along the way, he befriended a demon of waves named Negagen. However, Exetior later started a war with the Highests after being exposed, but was backed up by Sark and Pervision, as well as Negagen. Exetior lost the war via being shot with 16-guage pellets from a Browning Auto-5 and was stripped of his powers and banished to Hell, turning him into a demon of sharpness. Four thousand years later Exetior would break out of his prison due to outbursts from the Master Emerald, he escaped, being pursued by the guards of Hell and heading to Mobius, he found Sonic the Hedgehog and copied his appearance to hide out in his body.

Exetior tried to possess Sonic, but was unable to because it was protected by Creep. Creep told Exetior that Sonic's strong will made it difficult for him to be possessed. However if he three main parts of determination were destroyed (Tails, Knuckles and Eggman), it would leave him powerless and possessable. Exetior agreed to this choice and temporarily possessed Sonic's body.

Exetior appears in a secret involving him taking in Sark's Amy (Rosy) due to Sark's torturous and abusive nature towards his servants. He instructs the girls to keep Rosy company while he attends to a meeting with Exeller. After his meeting he meets Rosy again, who starts flirting with him. Exetior attempts to deny these feelings and notes how she should be going back home. Exetior later returns to save Rosy from being tortured by Sark, starting Sark's hatred for the demon he thought was his friend.

Killing innocent animals, stealing souls to make himself stronger, demonizing mobians, attending meetings with other demons, plotting.

Put an end to the Highests' activities of constantly erasing and recreating Mobius (Ongoing), conquer Mobius alongside his army and save it from being erased by the Highests (Ongoing), protect Rosy from Sark (determinant, succeeded).

Erasure (formerly), super speed (from Sonic's body), super strength, possession, stealth, flight, spindash (from Sonic's body), teleportation, corruption, reality-warping, murder skills, demonic powers, mind-walking, shapeshifting, telekinesis, immortality, piloting skills, demonization, manipulation, charisma, leadership, genius-level intellect, intimidation, harnessing chaos energy, super Exetior transformation (from Sonic's body)

Negagen (best friend and apprentice), Pervision, Exeller

All-Father (the Highest), Stich-Lite (the Highest), X (PC Port), Chaos Hunter

Exetior may seem ruthless, but he does everything to save the planet Mobius from being erased by the Supreme, which means that Exetior has an attachment to things, for example to the same planet Mobius. Exetior can actually treat servants, allies and friends with care and respect. Exetior has so all the secular manner of speech. Exetior is more relaxed and balanced than other demons of sharpness. He can be quick-tempered, but he is able to calm down