I guess you did not watch Season 3 yet? He is the evil-ER version of Megatron. In his universe, when he and Optimus had a disagreement over how to reform Cybertron, he killed him and took the Matrix way back then, meaning the Cons won the war and he started taking over the universe... but with the Matrix he could create perfect soulless Decepticon soldiers (who look like Tarn) hence he also destroyed his own Con followers, not needing them anymore. This universe's Megatron stole his Matrix and tried to come up with ways to stop Megatron X, but they all failed. He asked Prime for help in the end, admitting his counterpart became the monster he never wanted to become. It was a really great idea. Dude, you must be new here. Don't start arguments about "G1 is better" stuff, we all have been over that like, decades ago. Don't tell me you will bring up the "Trukk not Munkey" and "Rumble is Red/Blue, Frenzy is Blue/Red" arguments too? Talk about topic necromancy.