Omega Lock

Eons ago, the lifeforce of Primus was divided into the four Cyber Planet Keys and scattered across the galaxy. The Omega Lock is the device that the Keys join with to reawaken Primus's power.

Fiction
The Omega Lock was located in the Rust Sea, disguised as a nondescript object in the barren wastes. When the four Omega Keys were brought to it, however, its true nature was revealed. The ground transformed and pillars rose from the ground, forming a portal. Optimus Prime described it as a link to the AllSpark.

After a standoff, the Decepticons gained control of the Omega Keys and plugged them into the Lock, activating it. Megatron used it to restore a nearby building to pristine condition before sending its power through a space bridge to Earth, where it created a huge fortress. With the knowledge that Megatron intended to cyberform Earth, Optimus used the Star Saber to destroy the Omega Lock, causing a huge explosion. The Omega Lock did however manage to create a fortress which Megatron would use as a new base of operations.

Despite or perhaps because of its semi-divine nature, Optimus Prime believed that the Lock could still be repaired using the Forge of Solus Prime. Despite being mortally wounded in the Decepticon's attack on the Autobot base, he commanded Smokescreen to use whatever power remained in the Forge to repair the Lock, and through it, Cybertron. Smokescreen decided, against Optimus' intentions, to repair his fallen leader with the Forge. The upgrade, however, left the hammer powerless and thus, dooming yet another chance to revitalize Cybertron through the Omega Lock.

When Megatron ordered Project Predacon destroyed after Predaking displayed intelligence, the destruction of the Predacon clones combined with the presence of Synthetic Energon resulted a violent but effective cyberforming of the cave. As Megatron still intended to rebuild Cybertron and cyberform Earth, he commanded Shockwave to begin the reconstruction of the Omega Lock, seeing Synth-En as the means of achieving his goal. The severe damage that Optimus inflicted to the Lock meant that human technology would be needed to successfully repair it. The Decepticons proceeded to engage in a series of heists to acquire the required materials, including twenty tons of nuclear control rods and a particle collider synchotron. Once they had the raw materials, the Decepticons rebuilt the Omega Lock directly on the underside of their ship.

To complete the formula for Synth-En, Ratchet was abducted and taken to the Nemesis to complete the project. With the completion of Cyber-matter formula underway by Ratchet and Shockwave, Megatron commenced his plan to cyberform Earth by ordering Soundwave to re-position the Nemesis warship high above Earth's atmosphere.

The Autobots engaged the Decepticons in a battle to save Earth aboard the warship, with Optimus and Megatron battling fiercely on the platform of the Omega Lock. Bumblebee valiantly attempted to bring the Star Saber to Optimus to use to destroy the lock, but Megatron killed him and he plunged lifelessly into the Omega Lock's energy field. The Omega Lock's power restored both Bumblebee's life and his voicebox, and he took the opportunity to terminate Megatron. With the warship fully secured and under the control of the Autobots, they fired the Omega Lock directly into Well of All Sparks, in order to reach Cybertron's core. The beam of energy struck the core, completely restoring Cybertron to a healthy glowing blue.

The Omega Lock, still attached to the Nemesis at the time, was destroyed during the Autobots' confrontation with Unicron.