Obtain All Three Pieces of the AllSpark:
1. Find Jetfire's Remains: During the "NEST Invasion" mission in Shanghai, you'll come across Jetfire's remains. Collect all three pieces of the AllSpark from his body.
2. Retrieve Megatron's Head: In "The Battle of Egypt" mission, go to the top of the pyramid after defeating some enemies. Here you'll find Megatron's head.
Gather the Cybertronian Machine Parts:
3. Seek Optimus Prime's Help: After obtaining Megatron's head, head to the Autobot mission objective in Egypt to talk to Optimus Prime.
4. Find Cybertronian Machine Parts: Optimus Prime will mark two locations on the map where you need to find Cybertronian machine parts. Locate and gather all the parts from both areas.
Revive Megatron:
5. Return to the Pyramid: Go back to the pyramid where you found Megatron's head and the AllSpark pieces.
6. Assemble Megatron: Use the control panel in the pyramid to place Megatron's head, the AllSpark pieces, and the Cybertronian machine parts. This will revive Megatron.
Once revived, Megatron can be selected as a playable character in the "Decepticons" campaign.