The Darkest Timeline

MEANWHILE, IN ANOTHER REALITY...

Looking out over the city full of terrified, insects, Ultragirl couldn't help but smile.
She soared above the frenzied masses, her cape billowing in the savage gusts of wind as she tore through them, moving like a bullet from a gun. They all looked up as she passed them, occasionally flying low enough to stoop to their level, only to knock them further down and soar skywards again, a reminder of how insignificant they were.
She was a god to them.
An angel of destruction, all flame red hair, flowing black cloak and royal blue with silver trim.
She neared the appartment building formerly home to her protégé, AlphaGirl. Laughing, she plowed through the building, observing as it crumbled in her wake, toppled and, finally, came crashing down.
Three months ago, AlphaGirl had tried to kill her. And, obviously, she'd failed. Nothing could kill her. She was a god. And now every trace of the stupid little girl who had dared challenge her was wiped from the face of the earth.
She smiled.
It was a good day.

A year ago, aliens had appeared, hovering almost directly over Jupiter City. They'd been peaceful, bestowed gifts upon humanity; the deposits of their engine fluid kickstarted evolution again, prompting the activation of a few repressed genes in roughly 1% of global population. The genes responsible for superpowers.  Jupiter City had been their first bastion, their staging ground. Until one young woman, desperate for power and control, had broken into the facility and thrown herself into a vat of the fluid. One litre was enough to bestow a lifetime of powers. She had literally drowned in it.
When she had emerged, Svetta Kistrun was dead. Ultragirl, the most powerful post-human on the planet, had stood in her place. She had destroyed the facility and torn the aliens from the sky.
She had killed them all.
Ultragirl simply could not tolerate rivals.
The next year had been spent assuring her dominance. Any who dared challenge her, she either killed or  enslaved. She was stronger than them, faster, she was invulnerable, immune to mind control, and her mere touch was enough to break even the strongest will.
A few superheroes had stood in her way. Gravity Man, Firebug, White Frost, Sleeper, Miss Mist and LightWalker. She could have erradicated them. But it was more fun to watch her thralls do it.
Despera, the embodiment of hopelessness, AlphaGirl, her gravity-bending protégé , Ditzcord, the brain-draining acolyte, Slowpoke, whose touch robbed victims of their kinetic energy, Nemesis, the daughter of the actual God of Revenge, and her consort, the Red Mask.
Together, they had broken all those who dared to defy them.
Jupiter City was a wasteland.
Jupiter City was their playground.
And she was bored of it.
Nothing in the city had provided any sort of challenge for her. She decimated its heroes, levelled its streets, bent everyone and everything to her will. And it was dull. She had tested herself against every example of strength in Jupiter City, and found them all lacking.
There were others, of course.  Those whose power did not come from the aliens. The demigods and the divine champions. The most famous of these, AntiWoman, had vanished recently, leaving her domain ripe for the taking. But this would also have bored her. Her rival was absent, and so there would be no joy in invading her city. And there was perhaps one other being on Earth who might provide a moment's diversion.
The queen of the Amazons, Hades' champion on Earth; Superwoman. Sat atop her throne of corpses -actual, real corpses- Curia smiled.
Her predecessor, the Amazon Lois Lane, the first Superwoman,  had fled with the Crime Syndicate to another world, leaving her the unquestionable ruler of Queen City. The Black Owl, she had killed. AntiWoman had fled this reality. There were none left to challenge her reign. She might as well have been a Goddess.
She was Superwoman.
She was the raven haired angel of death. The daughter of Hades. Wielder of the Lasso of Domination.
And this world was hers to do with as she wished.
Everything in Queen City was hers to command. Unfortunately for her, Ultragirl was not from Queen City. From Ultragirl's perspective,  her power was nothing more than an invitation.
Hence, she dropped out of the sky and turned Superwoman's throne room into a crater.

A pulse of  telekinesis sent the dust sliding from her body. Superwoman had no such luxury; brownish dust clung to her black, one-piece bodysuit, golden cape, dark metal shoulder plates and war bracelets.
Her face contorted into a mask of abject rage. Svetta smiled.
Screaming, Superwoman leapt at her. A telekinetic shunt hurled her back to the ground. The toe of her boot intercepted Curia's chin as she fell, and the lazy kick  threw her through a triad of high rise penthouses.
A distant sonic boom gave her all the warning she needed. Curia came at her, flying like a bullet from a gun, and a perfectly timed backhand, augmented with a wave of telekinesis, casually batted her aside. She heard another impact, and saw another building crumble.
"Like swatting a fly..."
She was disappointed. Perhaps the Goddess of Queen City wouldn't put up much of a fight after all.
A tank sailed through the air towards her. She made no move to avoid it, simply letting its armoured shell shatter on impact. She had hoped Curia had known it wouldn't have hurt her. The supersonic kick to the gut immediately following the projectile confirmed this.
She actually laughed when she heard one of her ribs snap.
She caught herself midair, transferring all her momentum outwards and downwards, hovering over the crater she created.
Curia came soaring towards her, fist first, and she effortlessly ducked the blow. The force of her swing spun the Amazon, and with a hefty kick to her backside Svetta sent her headfirst into the ground.
She landed. Let the Amazon pick herself up. Caught her by the ankle when she tried to fly away, swinging her and slamming her back into the dirt.
"Oh, we're not done. Not by a long shot."
The broken Amazon swung one last punch. Ultragirl caught it easily in the palm of her hand, gently squeezing until she heard every bone crunch. The Amazon screamed, writhing in agony. Ultragirl laughed.
Her other hand, she wrapped around Superwoman's throat. Her screams grew silent, her struggles still. Her expression softened, lips parting slightly, eyelids drooping.
"Feel that? The icy pain in the back of your skull? That's me. I've just read every thought you've ever had. And now you belong to me."
Looking up into the helpless, vacant expression of her latest conquest, Ultragirl couldn't help but smile. AntiWoman had gone to a new world, this she had learned from peeling apart Curia's tiny brain. A world of opposites. A world with its own heroes and villains. A world with strength.
A world with another Svetta Kistrun.  
As she crushed Superwoman's neck in the palm of her hand, Ultragirl gave an oddly thoughtful smile. It was forfortunate she'd left the one man with accesd to dimension-breaking technology alive. Doctor Zarkov was going to help her pay this new world a visit.