Sinnertwin biography
Like his fellow Terrorcons, Sinnertwin aka Twinstrike [1] is a horrific insult to nature itself. Sinnertwin frequently patrols the Terrorcons' lair with the hope of finding anything unfortunate enough to be alive in his presence. Then comes the killing, and what with his multiple heads and sadistic nature, this is not something one would like to witness.
Ironically, he's terrified of small creatures. Sinnertwin isn't truly loyal to the Decepticon cause, and has been known to work alongside the Quintessons. He can combine with his fellow Terrorcons to form Abominus. He has the most awesome name in Transformer history. No matter what Slayride says.
Spinister transformers
Sinnertwin, along with the rest of the Terrorcons, was first encountered when the Autobots went to Unicron 's head to stop Galvatron from acquiring anti-electrons. During the battle, his two heads argued with each other over which one would get to take on a particular Autobot; he menaced Kup , who claimed to have fought bigger monsters than Sinnertwin.
When the Terrorcons seemed successful in overpowering the Autobots, Grimlock ran off and quickly created the Technobots. Meeting these new opponents, the Terrorcons formed into Abominus and fought the Technobots' merged form of Computron.