Rotor Walrus (Light Mobius)

Rotor (MxYL) is the Mobius: X Years Later version Rotor Walrus. He was the emissary of the Kingdom of Acorn, helping to arrange meetings between the royal family and other groups. He continued various side projects regarding mechanics and inventions, often in sectret along side Cobar. After the timeline was altered, Rotor was imprisoned by King Shadow for having retained his memories from the previous timeline, but was eventually rescued by the combined efforts of Lara-Su, Sonic, Tails and Knuckles.

Mobius: 25 Years Later (Unaltered)
In this timeline, he is a close advisor to the royal family, helping them with their royal duties. However, through unknown means he and Cobar, a fellow scientist, discovered that there was damage to the temporal space-time continuum that, if left unrepaired, could cause Mobius to cease to exist. He later shared this information with Sonic, Sally, and Tails. They reached the solution to use the Tachyon Chamber Eggman created before his demise so that Knuckles (who was informed by Rotor at an earlier time) and Sonic could go back in time to prevent Mobius's destruction. However, while any danger to Mobius was averted, the status quo of the timeline was forever changed... (StH: #131, #132, #133)

Mobius: 25 Years Later (Altered)
Due to his Chaos Powers, Shadow knew the timeline had been altered, and in order to prevent the timeline from being reverted, he had Rotor and Cobar imprisoned, with Cobar presumably killed, while Rotor was tortured and beaten by Lien-Da. Rotor was later reunited with Sonic, Tails, and Lara-Su. They were later freed by Knuckles, who as it turned out, still had his memories of the previous timeline, and Rotor was taken to the hospital by Lara-Su. (StH: #166, #167)