Mandroid

Dr. Meridian was at one point recruited for the Transformers war. He worked for the humans as a scientist to help fight the Decepticons. At one point, his base was attacked by friendly fire from the Autobots. Numerous people were injured in the explosion, but Meridian was saved thanks to his Arachnamechs. However, Meridian would end up losing his right arm and replacing it with a metal one. Eventually, the war ended when Megatron reformed, however, Meridan couldn't let go of what happened to him and held a grudge against all Cybertronians, seeking to eliminate them so he could be the "hero" the planet "needs."

Doctor Meridian
Mandroid
Mr. Mandroid
Agent Schloder

Attempted genocide
Mass Murder Treason
Terrorism
Conspiracy
Crimes
of hate
Unethical experimentation
Unjust imprisonment
Mass brainwashing
Mutilation
Kidnapping
Torture
Child abuse, Piracy
Computer science Espionage, Identity theft, Development of illegal weapons and Illegal use of weapons

The loss of his arm and the deaths of his colleagues during the height of the great war between the Autobots and Decepticons had turned Dr. Meridian into a cold, brutal, vengeful, and murderous scientist. He enjoyed torturing humans and Cybertronians alike, and was willing to resort to anything, no matter how low he had to stoop, to get what he wanted. That included striking down those who were weaker than him or utterly defenseless against him, increasing his size into a monstrous being at the cost of their humanity, and disposing of those who outlived their usefulness.
At the same time, Dr. Meridian was an intelligent and extremely evil villain who displayed a gift for technology. It was he who designed and improved the Arachnamech robots and other devices in his revenge against the Cybertronians and those who stood in his way.
Despite becoming a terror greater than the worst among the Decepticons with his monstrous final upgrade that reflected such a fact, Dr. Meridian remains a shell-shocked veteran and a tragic figure that one can still sympathize with.
However, he eventually let his resentments and the pain of his losses consume him and despite all warnings, Mandroid never learned to see sense and refused to see reason whenever he was given the opportunity instead of motivations to be better than those around him; this ultimately led to him paying the price for his sinister and evil attitude.