In a faraway universe...
There exists a planet of machinery and circuitry, completely composed of metal down to its very core. It has consumed entire worlds at several points, leaving them as shattered corpses, their remains scattered across space. Great gas giants, dwarfing their more solid brethren, weren't safe either. Tendrils of steel drained whatever resources existed within their misty surfaces. Even the stars themselves fell prey to it. Great machines, constructed from the pieces of the dead worlds it consumed, surrounded the suns it planned to devour, resembling a feasting swarm of locusts. They weren't fully drained, at least not instantly. The steel planet slowly leeched power from them, a steady consumption. It continued to expand its reach, going from little more than a dozen enslaved suns to eventually millions of subjugated stars. On the night skies of several billion worlds, the dimming of the stars was seen by their inhabitants. Those advanced enough to truly see what was happening were both amazed and horrified at the scale of it all. To them, it was as if a god reached out and blotted out their skies.
However, beneath all of this metal and wires and silicon, lay a singular driving will responsible for the mechanical world's all-consuming hunger. This consciousness was once flesh and bone, though still godlike compared to most anything in the universe. He had destroyed entire worlds and the people foolish enough to step into his path were wiped out as if they had never been. Until one day on an insignificant backwater planet, a monkey with an aura of gold defeated him utterly, sending him into that planet's sun. He had to thank the fool though, since if it wasn't for that debacle, his apotheosis would have never occurred. There was no better way to display gratitude than turning the monkey, along with the prince of primates, as batteries to power his great body. They are now empty husks, and have been so for the longest time, but that no longer matters when the stars themselves are under his command. His power was not the only aspect which increased, however. When he takes a world, he takes everything from it, including their technology. The knowledge he gained matched the energies powering him. With this knowledge, he will soon have the power to cross over to new universes. He will send his avatars, silver androids shaped like his former self, to these worlds as he did to other planets before and sweep away all resistance, taking delight in the inhabitants' horrified expressions, for there is still enough left of his past self to do so.
Soon, nothing will be out of reach.