Disclaimer: I do not own Arrowverse or anything else you may recognize

Got this idea from 9024multiverse so thank you very much to him. It's a pretty nice one.

Last warning. If you're a fan of Arrowverse Kate Kane, this is not for you. So look away right now. I don't like flames.

Hope all enjoy.

Earth-99

"What are those?" Kara Danvers asked Luke Fox as she spotted some display cases with items displayed in them.

"Mementos from Batman's greatest victories", Luke Fox said as Kara looked at them all. One was a card of the Joker with blood on it. Her Earth had one too, whom Batman constantly took down and put in prison but he always escaped. She was glad she had never met that sick person.

Then she saw a question-mark shaped cane. The Riddler's cane obviously. That man had some puzzling riddles for sure.

But obviously, these mementos meant this Bruce wasn't as virtuous as the one on her Earth. He was clearly taking some enjoyment out of what he was doing. The killings he was committing.

Turning to Luke, she said with disgust in her voice. "You mean trophies."

He just nodded lightly. Kara turned back to the displays, a little disturbed now.

But what she saw horrified her completely. She was horrified she couldn't even speak for a few moments. Glasses. Broken ones. With blood on them. But she would recognize those glasses anywhere.

"Those belonged to Superman, his alter ego at least", Luke said, confirming Kara's worst fears. Bruce on this Earth hadn't just started killing criminals. He was a sick person who had lost all sense of morality.

"Bruce killed this Earth's Superman?" Kara asked, shaking with fear and rage. Rage for her cousin's dead doppelganger.

"Who do you think put him in that exoskeleton?" Luke asked as she looked between the glasses and him. "Yeah. Big mistake."

But then she noticed something from the corner of her eye. Something else in one of the display cases. Something that increased her shock and horror tenfold.

Batman's mask!

It was broken, and there was blood on it.

But how could that be?

Unless, the person wasn't actually Batman.

Turning around to face Luke, she asked with a snarl. "Who is the man talking to Kate right now?"

Luke began. "Oh don't you know already? He is Bru-"

Luke was cut off when Kara sped up to him in a second and wrapped her hand around his throat, lifting him up as he gasped for breath. "Who is he? Tell me the truth!"

She put him down and gasping, he said. "He threatened to kill me if I told anyone!"

"What?" Kara asked.

"He is not Bruce Wayne! He is Thomas Wayne Jr. his twin brother!" Luke revealed, horrifying and confusing Kara.

"What?" She asked.

"After their parents were murdered, Thomas Jr. went off the deep end, getting into fights more often and brutally beating up other kids", Luke said as Kara listened. "He eventually went his own way but returned to Gotham years later. After seeing what Batman was doing, he dressed up as a more brutal vigilante and called himself Owlman. He came into conflict with Batman many times. Eventually, the two figured out who the other was but Owlman killed Batman and assumed his identity, with none the wiser. And then he killed all the other heroes by going through Batman's contingency plans for all of them!"

He then fell to his knees, shaking with fear as Kara quickly changed into her suit.

"Do you understand how many people, how many worlds are going to die?" Kate asked, trying to convince who she thought was her cousin's doppelganger to help.

"Well, if they're anything like this world, maybe that's for the best", 'Bruce' said as Kate stepped back, eyes wide in horror.

"How can you even say that?" She asked.

"There was no hope for this world", he said.

"That's because you killed Superman and Batman."

They turned to see Kara walk in as she said. "This guy's not a Paragon of anything. I was right. We can't trust the Monitor."

Turning to him, Kate asked. "What did you do?"

"Clearly what you couldn't" he said coldly to her.

"How was he a treat?" Kate asked.

"Strange visitor from another planet comes to Earth with powers and abilities far beyond those of mortal men?" He asked, sounding like a paranoid man. He looked to Kara and said. "Clark. Clark always said yes to anyone with a badge or a flag. He gave them too much power. My parents taught me a very different lesson life only makes sense if you force it to."

"And Batman?" Kara snarled as Kate looked confused.

"What do you mean?" Kate asked.

"This guy is not Bruce Wayne. He is his evil twin, Thomas Wayne Jr. He calls himself Owlman. He killed Bruce and took his place to fool everyone", Kara revealed as Kate glared at Thomas, rage and horror showing clearly on her face.

"Ah! Bruce!" Thomas said as he paced around. "Always the better one of us. Or at least that's what others thought. Bruce was weak! Even after he saw them senselessly killed for jewelry, he couldn't man up and do what it took! He put them in prison or Arkham Asylum, and all of them walked out or escaped! A week later! A month later! It never made a difference! And when I tried to tell him about my side, he gave me the bullshit self-righteous lecture. 'We are not murderers. We are better than them.' Oh right! When they get out and kill, the blood is on his hands as much as theirs! He was part of the problem! He deserved to die! They deserved to die! All of them! The way mom and dad died!"

Kara and Kate actually jumped at Thomas' passionate and enraged outburst. He had carried is point of view to the extreme.

"That still doesn't make killing right", Kara protested, only to be sent flying off with a punch.

She groaned as Kate ran to her while Thomas revealed Kryptonite in his suit.

"A little souvenir from the old hometown", he boasted.

Kate helped Kara up as she said. "You really think you can take us both alone in that?"

"No. I don't", Thomas smirked before pressing a button. Immediately, red sunlight filled the room, making Kara look around in horror.

"All right. You took her out, but how will you beat me in that?" Kate boasted with a smirk as she tried to punch. To her horror, Thomas blocked effortlessly.

She tried to free her fist from his grip but couldn't even budge it as Thomas pressed another button on his suit with a smirk and it came off, revealing his body was still physically fit and healthy.

"I was never broken. I took Clark by surprise. This was just to throw idiots like you off", Thomas smirked before twisting Kate's hand, making her scream in pain.

He then threw her to the ground and stomped on her chest, making her scream in pain as Thomas roared. "YOU THINK YOU'RE BETTER THAN ME!"

Kate had told Thomas everything about herself during their talk, and Thomas had never been more disgusted by a person.

Picking her up, he punched her face multiple times, breaking her nose and splitting her lip as blood trickled down while he roared. "YOU DID NOT WANT TO GIVE YOUR PEOPLE HOPE! YOU ARE NOT EVEN THE STUPID KIND OF HERO! YOU JUST WANTED THEM TO SEE YOU'RE A WOMAN! YOU LET ALICE WALK AWAY EVERY TIME YOU TWO MEET! YOU'RE JUST A SELFISH COWARDLY PERSON WHO DOESN'T DESERVE TO BE CALLED A HERO!"

With that, he threw her down. Kara tried to help but was kicked away as Thomas grabbed her arm and twisted it, making her scream in pain as he said. "YOU'RE JUST AN EGOTIST WHO PRETENDS SHE IS THE PARAGON OF VIRTUE AND HEROISM! SO DON'T YOU DARE PRETEND YOU ARE BETTER THAN ME! BECAUSE YOU ARE MUCH WORSE THAN I AM!"

With that, he grabbed the dazed Kate in a chokehold and as Kara got up, there was a sickening crack.

"NOOOOOOO!" She screamed in horror and grief as she saw her new friend's limp body collapse to the ground as Thomas got up, looking down at her coldly.

Kara ran to her dead friend, sobbing over her as Thomas said. "You feel the anger, don't you, Supergirl?"

Looking up at him with anger, she asked in a raspy voice. "Why?"

"She is not a hero. Just a self-righteous bully pretending to be one for credit", Thomas sneered at her. "Her Earth and Gotham City are better off without her. She didn't have the guts to get her hands dirty. She constantly let Alice walk away. She was part of the problem. And so are you."

Just before he could attack Kara, he was hit by an energy blast that disintegrated him. Kara turned around to see Mar-Novu lowering his hand.

"Why did you send us here?!" She demanded, outraged. "This psycho just killed my friend!"

"And that is the reason you were sent here", Mar-Novu revealed to her horror.

"What?" She asked, not believing what she had just heard.

"Kate Kane was an egotist who always wanted to be seen as better than everyone around her. And you couldn't see it", Mar-Novu said. "You yourself have egotistical problems, Kara Danvers. You have fallen from who you used to be. Thomas may have been a psychopath, but what he said about Kate was the absolute truth. I did this to show you what your ego can lead to. There is still time for you to abandon the ego, or one day you will wake and realize you are no different from Kate Kane."

Kara just scoffed, not listening to the Monitor for now. But they eventually returned to the Waverider where the Paragon of Courage was revealed to be Earth-167 Superman, who was the most powerful version of her cousin Kara had met so far.

She told him of the matter, and while Clark-167 didn't agree with Mar-Novu's extreme methods, even he agreed that Kate was an egotist and part of the problem. She didn't deserve to die, but she definitely deserved to be kept as far away from any kind of superhero suit as humanly possible.

That started changing Kara's perspective, and after her Earth was merged with Earth-1 and the Earth from which Black Lightning came, she decided to finally abandon her ego and apologized to Lena for everything wrong she had done, making Lena apologize herself. And Kara also never criticized some of her friends for keeping Kryptonite as a contingency again, because who could blame them?

Not having toxic influences like Kate Kane in her life really did wonders for her line of thinking.

And done.

Now this was my opinion on Arrowverse Kate Kane. If you don't agree, fine. I don't care. You have every right to your own opinion. But I don't want anyone spouting flames.

The Owlman idea I got from 9024multiverse and he helped me with this so thanks a lot to him for this.

And honestly, even in the exosuit, Bruce (Thomas here) could have beaten Kate easily and snapped her neck instead of the BS we got in the show.

Anyway, hope everyone enjoyed this and see you all next time with another update.