Nemesis Prime

"...The black hole sucks in Megatron, Starscream, Demolisher, Hot Shot and Red Alert, and they awake on a strange planet which seems drained of all life.

Here they are attacked by 'Nemesis Prime', an evil clone of Optimus, complete with black Starsabre and near indestructibility. After several chilling encounters with him, the Transformers are left down for the count.

As Nemesis Prime makes his final attack, a sudden burst of green light from out of the sky pulverises him. This separates into the five Minicons that teamed with these transformers, who proclaim that 'the fighting must stop' before reformatting their partner's bodies to save them. Megatron becomes the purple and white Galvatron, Starscream is now blue, Demolisher and Hot Shot get spiffy new red and white, and Red Alert is now orange and silver. At this point, Nemesis Prime suddenly appears out of the sand, four times bigger than before. His reappearance coincides with the arrival of the Autobots in their ship. Prime, bonding with Overload, leaps out of the ship, and takes out his clone..."