Nexus Prime became a Combiner as a result, but are there any dimensions where he (or Thirteen, including you) was a Combiner, Titan, Headmaster, Targetmaster or Powermaster?
My brother Nexus Prime can divide and recombine himself in countless different ways, but it is rare for him to specifically separate his head to become its own being—and even if he did, the greatest benefit of the Headmaster process is the bringing together of two different beings with their own perspectives, creating a greater view of the world than either could manage alone.
There is, however, an exception: in one divergent timeline, Nexus was critically wounded in our battle with Unicron, the dark giant's Dead End antibodies converging on him and crushing his cranial unit as he provided cover for our assault on Unicron's core. When the battle was ended, we mourned the loss of one of our own—but Micronus, ever insightful, realised that Nexus's spark still burned. To save his life, Micronus used the power of his Chimera Stone to bond with Nexus, changing to become a new head for our brother's dormant body; Nexus Prime was reborn, becoming Modus Prime, a new being that was not the same as either of their predecessors. I admit to having trouble adjusting to the change, at first; it was Onyx Prime, who was always close to Micronus, who helped me to see how Nexus and Micronus lived on in our new sibling.
As for the rest of we Primes, the most common sort of bonding we undergo is that of the Battle Master; for instance, Safeguard's starfighter mode doubles as a Galactic Forceblaster for me to wield, while Solus Prime has been aided in her smithing by the hammer form of Malleus Minotaurus. Otherwise, my sister Metroprime has been referred to as a "Titan" in the past for her mighty frame—and, of course, Energoa's studies of the energies of the universe have often led her to investigate the science of binary-bonding. I remember one time that she bonded with a Headmaster, Targetmaster and Powermaster at the same time—no foe in the universe could stand against that triple threat!