(this story is meant to be read as a continuation of the Man of Steel continuity of Superman. If you wouldn't like the ending spoiled for you, please stop here.)
"...and that's it. The people are calling him a Super-Man."
The man sat alone in his tower, his majestic throne facing the massive skyline of Metropolis City. The meek voice that came from his speakerphone had just finished recounting to him a tale of awe and wonder, of an alien that had become the saviour of mankind. One that pushed the very limit of feasibility, that defied any notion of common sense and seemed utterly fantastical.
Yet the man was not amused.
"And this...thing, it has been allowed to walk among us?"
There was an awkward pause on the phone.
"Allowed to...sir, with all due respect, he just saved the planet from annihilation -"
"Might I ask you to repeat, from whom?"
Another pause. The man had put his secretary in a tense position.
"From his own kind."
"Ah, and might I further inquire, how did he put an end to this threat?"
"...he neutralized their leader, didn't he -"
"It snapped the other one's bloody neck!" the man belted into the phone. "It kills, this thing does - the last of its own kind, no less! Yet even now this creature roams free, patrolling our skies like some hawk seeking its prey, like it owns us!"
She had nothing left to say to him. Rising from his seat, he ended the call and shifted towards the glass pane that revealed the entirety of Metropolis City to him. Even now he could catch glimpses of the thing - a flash of blue here, a crack of red there. With every passing day it moved public opinion more and more in its favour, working ever so hard to appease the masses with his parlour tricks and shows of altruism - but to what end?
Such lightning-fast speed, such grace, such beauty in motion was beyond anything which man could aspire towards. It danced and darted about the realm of men like some Greek god, fooling about and toying with mortal affairs while never quite being bound to or affected by them. To call him a "Man" seemed like a cruel joke, an affront to all of humanity - for it made a mockery of our ultimate potential by its very existence. This alien god, in being hailed as a man, would seek to become our very own Higher Power.
This man knew human potential, and he knew it well. He was at his physical peak - but only because of intensive training and a disciplined level of regimentation. His mental prowess was unmatched, though only as the end-result of decades of study and honing his varied crafts. All of his life was dedicated to the pursuit of this one goal - the realization of the perfect man, the ubermensch. He was not so petty that he would deny others the same quest, but for this alien creature to make himself known as a 'Super-Man' was unforgivable.
For the man would bow to no alien god - no, Lex Luthor would bow to no one. If no one else could see what danger this creature posed - no one seemed to, heavens forbid - then he would have to take matters into his own hands. He would become the champion of mankind, and rebel against the Super-Man no matter what the cost.
He would set out to prove to the world that the Man of Tomorrow had been borne not from beyond the stars, but from the Earth itself. In so doing, mankind would aspire to itself - not to something it could never be. This was to be his destiny, his heroic quest.
Lex Luthor would put an end to the Superman, and save the world.
