Unicron, the Ultimate Evil of the Aligned Continuity.
Transformers: Aligned Continuity is a continuity animated franchise that is in the Transformers franchise. They may have been several villains done committed plenty heinous crimes, but none have compared to the Bringer of Chaos himself, Unicron, with the most influence and biggest threat through out the entire series.
Close Contenders of the Ultimate Evil[]
Megatron[]
Before the events of the story and plot, he became the leader of all Decepticons, he is responsible for Cybertron for being destroyed is the direct cause of the Great War with Optimus Prime, lead Cybertron to rot, and as around the show, he went through a 3 year absence for search of Dark Energon, constantly done other heinous crimes for his willing through out the story, and once ruled Cybertron in the Season 3 finale.
He ultimately, despite being the main antagonist of the show, he was a pawn to Unicron by the end which led his redemption, and fails in threat level and influence to Unicron as well.
Starscream[]
He does backstab Megatron and tried taking over as leader multiple times, just to grow his pride as leader of the Decepticons and and take control for himself. He ditches some of his minor redeeming qualities like his pragmatic friendship with Knockout and ditched his loyalty for Megatron at the end of the series and attempts to take the throne before being attacked by Predacons.
He still fails as a second in command of Megatron and fails the influence compared to Megatron and Unicron's in comparison of the show's story.
Shockwave[]
He is responsible for creating devices that killed almost entire Predacons race, and his loyalty for Megatron was only pragmatic, and does get away from his crimes.
However he was still a pawn to Megatron and fails influence as well compared to Megatron for him being leader of the Decepticons while unfair to compare with Unicron for Shockwave's unique crimes by with his devices.
Airachnid[]
She clears herself as a Queen and similar to Starscream, betrays Megatron and makes herself free to her own biding without Megatron in his ship, despite Soundwave defeating her twice for his loyalty to Megatron. However, she fails the influence in the story to Megatron as his goal was to conquer his home planet and Unicron who wants to conquer the entire universe.
Megatronus[]
Megatronus Prime is one of the original Thirteen Primes and the overarching antagonist of the first season of Robots in Disguise. He is a notable villain in the continuity due to being the namesake for Megatron, killing Solus Prime, and causing the Alchemor to crash on to Earth. By the events of the show, he proves to be one of the more heinous villains by attempting to destroy both Earth and Cybertron out of revenge for being exiled.
However, he still is outdone by Unicron in terms of both scale and influence, especially since he never reached the same threat level as the latter and was only the most influential threat in Robots in Disguise.