mmm lets see, a planet eating god with a severe dislike of life in the universe, who could it be?
and the answer is....
UNICRON!
older than existance itself unicron went on well heck on a path of decimation, then came primus, lord of the gods of light, they battled on and off for millenia, destroying the universe as they went (the irony wasnt lost on them ofcourse) until nothing remianed, his work done unicron went to rest....but not all was gone.
the remaining matter, energy and life in the universe drew together, and then BOOOOM! the big bang, the entire universe was once more born, unicron being a heavy sleeper didnt notice.
immagine his chagrin when he wakes to find a new universe teeming with life, and so he went about blowing stuff up again.
but this time primus was ready, and led unicron to a remote place where they battled for the final time, primus was defeated, so he fled to the energy realm and continued the fight there...and was defeated again, but, primus had lead unicron into a trap, and sealed unicron and himself in small piles of rock and junk.
unicron was annoyed. but found he could shape his prison, and consume the life forces of the universe to make himself stronger.
and then TWO forms...to...hit the universe i guess.
primus too hadnt been idle, he had made a planet teeming with life, life that too could transform from one form to another.
unicron sped towards primus, slowly atfirst, so he could gain power, but quickly speeding up.
until the last stretch, when he shut himself down and drifted the rmaining way, so that primus wouldnt sense his coming, until it was too late and unicron was tearing cyberton apart, the transformers fought back but many died in the struggle (scorponok, trypticon and thunderwing for example) but eventually optimus made the final sacrafice and destoyed unicron with the newly restored matrix of creation and himself in the process.
but unicron did return, for a dark god like himself cannot be truly stopped.( oha and primus died
)
edit: and heres the main man in robot form (my avatar is planet form)