The Ageless: He was guarding the map to the Omega Lock for well over 1,000,000 years prior to the start of the series. And considering the fact that he's a Transformer, he's not going to be dying from age anytime soon.
Vector Prime: They were destroyed because I left them... No! This will not stand. I am a keeper of space and time. I can see through time. I will travel through time. I can change time. I will change time!
Took a Level in Jerkass: Between Energon and this series, he fell out with Optimus Prime regarding the life of a stranded astronaut and took off into space. When he first appears in Cybertron, he and the other Autobots don't get on, but he gets better as the series progresses.
Awakening the Sleeping Giant: Before the Autobots arrival Metroplex was only ever interested in building things. After the Decepticons start making a mess, he takes action.
Axe Crazy: Downplayed compared to Megatron, who is completely nuts, but he's basically the new version of Cyclonus.
Mid-Season Upgrade: After suffering massive damage. A ghostly Megatron appears and saves the dying bots life. Alomg with granting ole Ceumplzone a new look and some extra firepower.
Doesn't help at all. A couple of episodes, a couple of good shots which ultimately become Hope Spots from his point of view, and he's straight back to being a Butt Monkey (despite the Badass new Hot Paint Job).