Been mulling over some ideas for Powermaster Transfromers lately.
-Powermasters basically were the next step after Headmasters- which used little guys that turned into engine blocks, to unlock the transformation ability of the larger robot. And heck, they've brought back almost everything else, so why not?

Well I figured as the smaller (persumably Cyborgs) units transform into engines- they employ technology similar to what I've seen in a recent Iron Man comic. Essentially using human biology as an energy catalyst- being symbiotically bonded to a powercore and increasing it's output exponentially! Kinda like those pods in the Matrix, but with more kick.
Combining something like that with a large Cybertronian body would result in some kind of Energon Overdrive. (simmilar to the effects of the floating island in Beast Wars) Power levels might even increase in times of duress. Plus there's something poetic (or gross?) about having a human heart at the core of an Autobot.
Of course there'd be weakness to this setup. Remaining combined for extended periods would be a strain on even an enhanced metabolism- meaning the human component would be subject to fatigue and burn-out. Overexertion might even result in the Powermaster Starving to death. Also, cyborgs have shorter life spans than Cybertronians, and would eventually have to be retired, replaced, and broken in. (Which is why i drew Hi-Q as a female.... yeah, needs to be cleaned up... shush >.<)

I'm still not sure how the psycology of the merger should work tho. While the Cyborg funcions as an independant personality- i figure the vehicle is only a partial personality- possibly sparkless until they combine. I figure it should be more than a human piloting a Cybertronian body tho- upon combining- the larger body might function as an external memory device- plugging the memory and life experiences of the bot into the powermaster- but emotions and responses to those memories would be handled by the human component. The main idea being that the resulting personality is a combination of the two entities.
Yes, I seriously spend hours mulling over this stuff... >.>