Unicron, the Cybertronian god of destruction and Primus' evil brother, is a planet-sized Transformer who has become the Earth itself. Only to be reawakened by the prophecy of the 47 spheres aligning together, he is someone whose shadow likes to hang during the show with the influence of both the Dark Spark and his own blood, called Dark Energon, which is known to revive the dead and become his own personal undead army to destroy Cybertron. He also has the power to create avatars from rock to take on Autobots and Decepticons, small or large, combiner or not. Unicron can even use his Anti-spark to possess another Cybertronian's body if they have Dark Energon flowing through them, whether in life or death, as his own personal vessel.

For this incarnation, the actor needs to have an emulation of the late Orson Welles' performance from Transformers: The Movie from 1986. You can also mesh the interpretations from Armada and Prime together to make him more menacing, dark, and brooding.