Dark Nova - Transformers: Prime

The main group of Decepticons (also referred to as simply "Cons"), lead by Megatron, in the 2010 computer animated series Transformers: Prime is much larger than in most continuities and are opposed to Team Prime.

In Transformers: War for Cybertron and Transformers: Fall of Cybertron, Megatron has come across a legendary element called "Dark Energon". He infiltrates Starscream's space station in order to corrupt himself with it. He then kills the Autobots' leader Zeta Prime and obtains the Omega Key, which then activates Omega Supreme. After Megatron defeats Omega Supreme, he goes to Cybertron's core and corrupts it with Dark Energon. Optimus Prime becomes the new Autobot leader, and heads into the planet to rescue Omega Supreme. He opens the Omega Lock into the core after Ratchet purges the Dark Energon corruption. Optimus discovers that he is too late to save Cybertron from the Dark Energon corruption, and the core must shut down for about one million years to survive. Optimus is giving a piece of Cybertron's spark for safe-keeping (The Matrix of Leadership). When Optimus evacuates the Autobot forces from Cybertron, Megatron tries to stop them from leaving. Silverbolt, Air Raid, and Jetfire try to stop it, but the space station transforms into Trypticon and crashs on Cybertron. Optimus and his Autobots then defeat Trypticon. Megatron has Trypticon rebuilt into the Nemesis. The Nemesis pursues the Ark, and then Megatron shoots Bumblebee. They go into a space bridge, and leave Cybertron to a lifeless wasteland.

The story is retold in Transformers: Exodus, Megatron started out as Megatronus. he was friends with Orion Pax and was a gladiator. His name was changed to Megatron, when crowds chanted his name. He and Orion eventually became enemies, and the Autobot/Decepticon division happened. The war began, and Megatron would be the Decepticon leader. The war begins, devastating Cybertron, causing all the Autobots and Decepticons to leave Cybertron.

By the time of Transformers: Prime, it has been three years since the Decepticons last attacked Earth and the Autobots still await their return. After the death of Cliffjumper, the Autobots fight to protect the Earth from the Decepticons and befriend three young humans while preparing for the return of Megatron, who has been missing for three Earth years. Megatron plans to use Dark Energon to raise an undead army of Cybertronians and defeat the Autobots. The Autobots destroy his space bridge and Megatron is believed killed in the process. Starscream becomes the new Decepticon leader.

After Megatron's apparent death, new Decepticon leader Starscream does not stray from Megatron's path and recruits several new Decepticons. Starscream attempts many missions to destroy the Autobots and find their headquarters, while keeping a shard of the "last" remaining Dark Energon that he took out of Megatron's chest. In the episode "Out of His Head", Megatron returns after an incident where he Takes control of Bumblebee's mind. Megatron then reclaims leadership of the Decepticons, keeping a strict eye on Starscream. After Starscream uses Megatron's share of Dark Energon, he tries to find more to once again bring back his "un-dead army". At the end of the episode "Partners", Starscream became an independent and hasn't been seen or heard from ever since. During the final four episodes of the season, the Autobots unwillingly team up with Megatron to battle a legendary threat to Earth's existence, Unicron. To defeat Unicron, Optimus uses the Matrix of Leadership. With this sacrifice, he not only loses the Wisdom of the Primes but also his memories of the war and his comrades, and joins Megatron as a Decepticon under his old name, Orion Pax. Orion would decode relics. The Autobots would save him and regain his memories, but the Decepticons continue to search for the relics Orion did decode throughout Season 2. When Optimus possesses the Star Saber, Megatron replaces his arm with an Ancient Prime's arm, so he could use the Forge of Solus Prime to turn a hunk of Dark Energon into the Dark Star Saber. Megatron destroys the Star Saber. Defeated, Optimus Prime retreats, and then decodes the final four relics, the Omega Keys, to regenerate Cybertron.

The Autobots got the first key, Knock Out got the second, and Starscream got the third. The fourth and final one was inside Smokescreen the whole time. After the Decepticons kidnap him, Knock Out uses the phase shifter to get it out of him. After finding out the purpose of the keys, by using the cordical pyschic cordial patch on Smokescreen. When Megatron leaves Knockout alone with him, Smokescreen and Knockout fight over the phase shifter. He sticks Knockout in a wall and leaves him there. He takes the one the Decepticons had and his and escaped the ship, starting a free fall battle. After, he went back to the base. Starscream them went to steal the three the Autobots had. Starscream, now with all 4, uses them as a piece offereing to rejoin the Decepticons and Optimus was pretty angry about it.

Dreadwing, angry that Megatron allowed Starscrean to rejoin the Decepticons, give Optimus the Forge of Solus Prime, and attempts to kill Starscream but is killed in the process, by Megatron. Knockout and Starscream use the keys and findout the location of the Omega Lock, Optimus already knew it's location and turns the Goundbridge into a spacebridge, and reforges the Star saber. They go to Cybertron, fighting off the Decepticons with relics, take back to keys and kill all the Vehicons. They go to the Omega Lock. Sadly, it's a victory short lived, as the Decepticon force them to give them back the keys, or they will expose Jack, Miko, and Raf to Cybertron's toxic atmosphere. The Autobots give them the keys, with Megatron uses to rebuild the Hall of Records, then he opens a space bridge, and tries to terraform Earth into a new planet called New Kaon. Optimus takes his Star Saber and cuts off Megatron's arm and destroys the Omega Lock, leaving Cybertron in it's liveless state forever. They retreat back to Earth, only to find that Jasper, Nevada has now been changed into a gaint fortress. The Nemesis lands there, and Optimus discovers they gave found there base. Vehicons start attacking the base. Wheeljack and Agent Fowler try and hold off the new Vehicons. Optimus has Team Prime split up to different parts of the country. Ratchet was last asking Optimus where he would go, Optimus said he would stay behind and destroy the groundbridge, so the Decepticons would not find them. Outside, Wheeljack's Jack Hammer is shot down by Starscream. The Decepticons blow up the base with Optimus inside. Agent Fowler and June Darby watch in horror. Megatron and Starscream go the remains of the base. Laughing about their victory, as the screen pans over to see Optimus's arm sticking out off the rubble.