Dear Vector Prime, Do you know anything about the green horned fella who was resurrected by Galvatron and killed by D-Void?
Dear Resurrection Recaller,
Ah, I had not realised fragments of that tale had reached your dimension yet.
Yes, back before the Quintesson invasion, the leader of the Random cult had turned to dark sciences in furtherance of his anti-Patterner goals. When mutating his own body wasn't enough, he found the ancient Basilica of the Primes, and unearthed the skull of the Liege Maximo.
My brother acted as Galvatron's mentor, whispering secrets and furthering the cult leader's aims, until they could amass enough Dark Energon to create a new body for the treacherous Prime. Now renewed, Liege sought to leave Cybertron, as Alpha Trion and Alchemist Prime became alerted to his resurrection. Alpha Trion led a Patterner raid against Random, finally extinguishing that cult, while Alchemist followed Liege Maximo and Galvatron into the far reaches of the galaxy.
Knowing his brothers would follow him to the ends of the universe, Liege Maximo sought to break the boundaries between dimensions, travelling to another plane of existence. Unfortunately for him, he chose the Dead Universe infested by the monstrous D-Void. Faced with a universe-ending threat, Alchemist Prime, Liege Maximo, and Galvatron joined forces, trying to return the dread harbinger to his own realm, or else destroy him. It worked, but cost Liege Maximo his life; the only remnant of the monstrous battle was a sphere of necrotic force, which was bound into the remains of the Liege Maximo, containing it.
Alchemist and Galvatron returned to Cybertron, the latter hiding the abominable Dark Spark where he felt no one would find it; while Alchemist returned to watching behind the scenes. All he told Alpha Trion of that fateful battle was that the Liege Maximo would no longer trouble them, which Alpha Trion took to mean that he had been imprisoned.
I believe that should fill in any blanks in the story—though I am unsure how much you knew already.