Where is Optimus Prime?

[Verno]

This gives me a vision of Optimus Prime, strung up deep in the dark centre of Cybertron like the Queen in Aliens, laying new Protoforms from the back of his trailer.

I meant more along the lines that he passed into Vector Sigma, like Alpha Trion did, not merged with it.

That is a horrific image though

Optimus Prime was reformatted as a Maximal known as Convobat. It says so in his tech specs (sorry, can't find an English translation atm - but the first sentence says that he was "the famous tractor trailer truck called Optimus Prime"). You guys can make up whatever alternate fan theories if you want, but that's the official story.

That's a fate worse than death right there.

And that's only in one of the miriad universes. Live a little Gok, voice an opinion or theory, this is a discussion of ideas, not canon.