Queen Mansion, Starling National City

In bed at Queen Mansion, Oliver and Kara, they had this relationship for years starting from the day it began a wondrous hope brought upon Oliver's perceptive eyes that glared into the beauty of an angel that saved him being locked in the pit. They spent the night together like always, and are uncertain what their future holds for them.

In the end of forty winks, Kara finally rises. She enjoyed her night with Oliver, which was undoubtedly last night.

Otherwise, why else would thrust a Girl of Steel to fly from her apartment all the way to the Queen's mansion. Or she may have lived her more days anyone would presume of them.

Kara steadily looks at the faint light gleaming from outside; no longer harboured in the dead of night. She looks over to her right; Oliver Queen sleeping. She didn't bother to wake him up. She remembered the come-to-pass scene, what originated it into a passionate moment. They are both superheroes, or in Oliver's case, the latter is a vigilante, that try to validate the safer parts of Starling National City.

She begins moving out from the bed by motioning in a blur, dressing herself, making herself prepared before exiting the mansion. Once done, she is immediately wrapped firmly by someone behind him. She would've instantly kicked into instinct but she knew Oliver was behind him, giggling.

They both exchanged kisses, and then parted with Oliver dressing up.

"So I assume the world's greatest archer has officially withdrawn from managing the company's operations", Kara said teasingly.

"Oh, I'm not relinquishing the one-and-only company that funds my superhero activities", Oliver assures her mildly.

Kara fires a raise of one finger up, a sign of gesture, responding Oliver. "Vigilante activities, you mean", Kara corrected. "Not superhero activities. How would Thea Queen think of it?".

"When I confessed her I was the vigilante, she had no qualms or frustrations on me. She was actually proud of me", Oliver replied.

"No wonder you trust her as to give her the chief of staff. A girl who was once arrogant, reckless, selfish, impulsive and immature spoiled teenager, now a responsible, dutiful, confident, disciplined adult", Kara said, showing strong signs of good impressions on Thea Queen's personality change.

"She's changed a lot", Oliver remarked.

"And who was it that she idolized?", Kara rhetorically said.

Rhetorical question caused Oliver to lightly chuckle. He admits if it wasn't for him still being alive, Thea would've been that same reckless brat that would one day get herself killed. He'd thank everything that'd brought his life to go on instead of dying in Lian Yu.

Queen Industries

Thea was swirling in the passages of the building until she heard clatters, prompting her to twist a glance; the noise came from Oliver Queen's office. She was very sure her brother wasn't lounging around in there. She got a phone call from Kara that Oliver's in the mansion. If it isn't him, then who is intruding Oliver's office.

Coming into Oliver's office, Thea perceived nothing in the room. The chair is cleared. Hasn't moved. Though her attention on a slight change courses her over to the desk. On that desk is a book. Thea doesn't recall Oliver the type to read books in his own office.

Stopping by the desk, Thea picks the book up, she opens it, thinking what it is. The book was already open so Thea went straight away to look at what's inside; pages. She saw some sort of green goo, much to her disgust. This book is definitely not Oliver's.

Just before Thea would move away, she came to realise the green goo was actually sentient; it rocketed into her open mouth. Thea could not scream. It was inside her mouth, squeezing into the internal side of her body. As that goo waggles down her esophagus, Claire feels her consciousness burning out as though her inner being drifts away from her physical form, which she can clearly understand because she feels herself becoming more numb. She's starting to suffocate. What force is lingering inside is dragging her out. Thea tried to fight it. The struggle causes her to collapse on her knees. The struggle is making even more difficult for her to regain control of herself. Then, Thea blacked out, lying on the floor.

The only differences made in Oliver's office since Oliver last appeared is the book and Thea's unconscious body.

Over a few seconds later, Thea's body started to twitch a hand up. Then slowly, her body started to trembly arise in an upright position. Her eyes remain closed. Her arms are hanging down even though she's standing, as if her body is completely drained. Her face started to peel off a very distinguishable smirk but in an evil way. "Feels weird to be different. Ah just some scrawny ass girl not fit for Mr. J", the lady said except it's not Thea's voice or its own mind in a perfect match with the body. It's not Thea Queen. It's someone else possessing her body rather than Thea. The being peered at Thea's breasts before shaking them, and subsequently squeezing them. "Knock myself out. Mr. J did say to get Mr. Queen's attention. I'll do just that". The person controlling Thea's body makes it move out of the office. Before it does, the controller stopped and did one last look; squinted at Thea's ass before slapping it hard. "Take back what I said, the bird's a chick. I know just what to do".

Elsewhere in Starling National City...

It all happened so fast for Supergirl. So quick. Supergirl never felt like she didn't have experience fighting someone on equal terms of power. Supergirl is flying in twirling directions. Hands firmly holding her head while Superman is thrown to many places. She could barely move because these fierce blows are very painful. They would kill her. No enemy would beat her that badly except quite a lot of villains that are as strong as her and her cousin. Finally, the throwing has ended suddenly. She no longer felt like she was about swing everywhere. Instead, this being dropped Supergirl. With her lying, Supergirl finally examines who her attacker is that disturbed her patrol over Starling National City. It's that Worldkiller that sent her to the brink of death: Reign. She seems to have turned her attention elsewhere as if someone is in the room.

Reign saw another being entered the warehouse; she is fighting the Green Arrow. As what it appears, she's bound to get the upper hand with her immense strength and speed to cover for it.

Green Arrow is able to avoid some of Reign's punches before rolling below the fist that could've ruptured his cranium. The archer slides past Reign.

Reign launches her leg over to the other direction, intent on hitting Green Arrow.

By instinct, Green Arrow backs away though barely. And seeing the leg hanging for a second, Green Arrow jabs an arrow from his quiver into Reign's leg. Reign growled over that pain. Oliver knew why: the jabbed arrow has kryptonite.

Bearing the pain, Reign shoves Green Arrow away. She plucks the kryptonite arrow out of her leg, which she briefly grunted through. She afterwards looks forward, seeing Green Arrow laid in piles of broken crates. She flies straight to Green Arrow only to get bulldozed. Its force rivals a Kryptonian. She glances, finding the charging Supergirl.

Reign breaks off Supergirl's rhino-assault. She throws a fist, attempting to hit the Kryptonian.

Supergirl evades a throwing punch before delivering a knee struck on Reign's torso. Supergirl afterwards fists Reign's face.

Reign returned to Supergirl, instantly gripping Supergirl's throat. She struck a knee toward Supergirl's abdomen. She flips Supergirl to the opposite so the latter would be facing up at the ceiling while her back is Reign's target. She in a hard way lays Supergirl down to her knee.

The sizzling pain drivers hard inside Supergirl despite her attempts to endure it. She rolls away from Reign before punching Reign away. She then throws a few more blows on Reign's face with the last hit touching hard on her chest.

Having enough of this, Reign pushes Supergirl away by charging against her, driving the way out of the warehouse.

Green Arrow finally recovered, gets up. He searches Reign and Supergirl only coming to see they're not here. Although, Oliver did spot a hole. He assumes that's where one of the powerhouses burst right through.

The archer exits the warehouse, still searching for Supergirl. The hole led to the waters. Green Arrow examines there. While watching, he lost his guard when Supergirl suddenly flew out, crashing Green Arrow, causing the latter to fall back.

Reign rises from the water. She was about to attack Supergirl but something suddenly pierced her eye, which she pulls out. It did not matter. What pierced her eye made Reign lose half her sight.. Then another thing hit her leg, then her shoulder. She grunted. Reign looked at who is firing arrows. She immediately discerned Green Arrow shooting arrows directly her. If she continues to stand around here, she could have an arrow struck at her heart. Besides, she has been depleted from her intense fight with Supergirl.

As many arrows as he can shoot, Oliver would do anything to protect Supergirl. He knows about a Kryptonian that died, a Kryptonian that's a hero to the whole world, a Kryptonian who was killed by someone who rivals his strength. He won't let this occur to Kara.

Reign finally flees, flying as far as she can away from Supergirl and Green Arrow. She will eventually come back for them. Time will tell for their inevitable fates by her hands.

Far off the area where she fought Supergirl and Green Arrow she had went. Reign falls like a meteor crashing into an alley.

Ending up at the alley, Reign slithers along the narrowed path. She can't stand anymore. It's like gravity treats her harsly as a result of failing to beat Supergirl and her ally. Or more or less the signals have grown weak inside of her to move forward. She nonetheless pursued wriggling further.

A stomped foot approached before her eyes; Reign stopped impulsively. She promptly looked up. When it began with looking at its purple boots, as her eyes rolled along upward, this being wore purple pants, and a purple coat. Became clear he was dressed in purple suit with purple shoes. She saw his hands; they are chalk-white. He looked deeper up, desiring to know who the strange boldly stands in front of her. She finally saw his head; like his hands, this man's face is chalk-white. He has green hair, and a stretched fixed grimace which is glaring her in a very pleasant way. It was giggling.

"Why isn't this an early Christmas present?", the being said to himself rhetorically. He then cackles. "If I had known Santa came popping by in the cast away, I would've written my most-wanted list of things I'd like to have...". This man started rubbing his crossed hands. "...for a special occasion".

Reign pants. No way to lift a muscle to rip this man's head apart.

"You've grown weaker than a locomotive. I've observed your fight with Supergirl", the being said, wandering around Reign. "Should be powerful enough to kill her. Supergirl should be dead. Instead you fight with her almost reaching a stalemate". This white-skinned man stopped moving, subsequent to staring her weak body. "No worries, lost child, Uncle Joker is going to make it all better". After giving that promise, Joker swarms the alley with gas, making Reign breathe it in. He gives the loudest laugh of the day to show his joy.

At the location where Supergirl and Reign battled...

Oliver knelt beside Supergirl who has been spending the time recuperating. He's glad Reign hasn't managed to kill Supergirl. An alternative ending in their fight would be Reign killing Supergirl. "If Reign had finished you off...", Oliver said before sighing, and looking elsewhere. "...she would've been your Doomsday".

"I don't think she ever was... I mean from now", Kara said. "I felt her punches. Admittedly, they were still painful. But the blows I took from her years ago, it felt like I was going to get hit by a train".

"She's weak?", Oliver questioned Kara.

Kara nodded slightly.

Turning away from Kara, Oliver gazed the city far off by the rivers. He thinks what if Reign can easily be defeat. His thought disturbed by a phone call.

Once Oliver drew his phone out, looking at the contact name, it was Thea ringing him. Thea quite likely is calling him because she's worried. Oliver acknowledges he hasn't spoken to Thea. Though this feels like it isn't the right time, Oliver had to take it. Thea might need him urgently. He answers the phone call, plugging to his ears. "Thea?", Oliver said mildly.

"Hey Ollie"

Oliver frowned in spite of hearing Thea's voice crystal clear. It was rather in alternative route more seductive; her voice's pitch is fairly low; a little raspiness was added to her voice. "Thea?", Oliver said in a questioning manner. He sounded awkward.

"Are you proud of me?"

Oliver responded with an awkward chuckle. "Of course I am, Speedy", Oliver said. He glances Kara, finding her expression the same as his. Even she found it a little disturbing when she heard Thea's voice with her super-hearing. Oliver then heard Thea's orgasms, which greatly disturbed him as though she is enjoying having a conversation with Oliver.

"Thank you, handsome. Why don't you come down in Star Club, and allow me to show you my moves"

The phone call shortly ended. Oliver lowers his hand down. "She ended the call", Oliver addressed.

"Boy... I had no idea Thea relapsed on get-high province", Kara exclaimed.

Oliver sighs. "She's not herself", Oliver said, looking away. He finds it hard to believe Thea would twist and return to her reckless side after all she and Oliver had been through; the loss of their parents; the loss of Tommy Merlyn; the pressures they went through.

"Star Club, was it?", Kara asked, even though she didn't have to.

"Yep", Oliver said, looking at the Kryptonian.

"Let's say we pay your sister a visit", Kara said, looking at Oliver.

Star Club

Swinging by the club, Oliver and Kara straight away came inside. A great deal of people so crowded it quickly sucked in Oliver and Kara's curiosity on whom the crowd watches. They walked deeper into the area, a little dark though shimmering lights popping up resolve this issue with looking in the dark. This light draws everyone's eyes to where the light sets forth a distinguishable view. What the light has aimed, Kara and Oliver saw a a slender Caucasian lady with brown hair completely naked attached to several men around her with eruptions of orgasms. It's all happening on stage. It's being done by Thea Queen.

"Kara!", Oliver said, wanting his sister out.

"I know!", Kara addressed. Oliver would ask her to remove Thea out. Kara ran in fast motion, heading toward the stage.

Oliver watched as Thea was finally removed from there by Kara in a blur.

Everyone wondered where Thea was when they perceived she vanished. Words of disapproval exchanged among the audience.

Oliver soon felt being dragged out as if he was latched to a speeding train pulling away with immense force. It was actually Kara taking him away from the club.

Queen Industries

Kara brought Oliver and Thea to a secret lair.

Settling swiftly, and ridding the nausea, Oliver swiftly razed a glare at Thea. "What the hell were you thinking?", Oliver said angrily. Thea's eyes were like a puppy. Raised a mention beforehand, Thea is a different person. "I thought we were way past that life".

"Gee Mr. Arrowboy, can't a girl have some fun?", Thea said in low-pitched voice. "Why are you always mean?".

Oliver was about to argue he wasn't but was interrupted by Kara.

"Oliver", Kara called.

Hearing Kara, Oliver turned to Kara.

"Someone has been here", Kara divulged.

Stunned, Oliver examined the lair, moving away from Thea to see if anything has changed in here. "No one's in here now?", Oliver asked. The lair isn't lined with lead except the path to get into the lair is. Lead, a Kryptonian weakness that prevents those species from being able to see with x-ray vision.

"Already checked", Kara conveyed, whilst dawdling the lair, searching anything that may help them understand who breached here.

Unbeknownst to Kara and Oliver who are way focused on who the breacher was, Thea had plans of her own. She formed a stretched sinister grin, staring both of them. She has shadowed this look of desiring to kill, now she's in here, she can end them.

The spreading search drew further to one part of the lair, making Kara stop by computers. It was on. No doubt someone was in here, and it was conducting on a computer. "Oliver! Get over here!", Kara calling for his arrival. What she sees is something was uploaded.

Oliver quickly came, standing next to Kara.

"Someone's been on the computer", Kara said. She sees Oliver inspecting the computer. "Did it take anything? Personal locations? Contacts? Any Justice League data?".

"No", Oliver said, confused. The intruder could've easily stolen intel. "The interloper never took anything. According to this, the gate-crasher uploaded something into the computer system".

"What did it put?", Kara asked.

Leading up to speaking was disturbed with Oliver feeling sharp thing piercing his back. It was the tip of the arrow.

Kara backed a bit away after being surprised with an arrow. It was on Oliver's back. She then saw Oliver collapse, much to her shock. "Oliver?!", Kara exclaimed, shaking Oliver to wake up; Oliver isn't making many movement. She turns around. Her confrontation with the attacker instead turns into getting set in blazes. The whole lair is lit in green light; green kryptonite. She looks out on the holder of kryptonite, who also used a bow and arrow on Oliver. That holder is neither her or Oliver. Kara did not perceive this coming. "Thea?". Thea Queen is holding kryptonite. The closure of green starlight surrounds Kara, coercing her to back away.

The holder is amused Kara would think she is Thea. "Ms. Queen is currently not hosting this shell, honey", she addressed.

"That voice?!", Kara exclaimed in surprise. "Harley Quinn?".

"Righty-ho Power Girl!", the being said.

"But you...", Kara said before pausing due to exposure of kryptonite biting her. "...you died...".

"Mr. J is the sweetest man alive, he made afterlife reject me into this real world to accomplish his dreams", Harley Quinn said, speaking in Thea's body. "Leaving his legacy on this planet with funs and laughter".

So the Joker is behind the strange behaviour of Thea Queen?, Kara wondered. Does make sense why Thea was seemingly back to her old ways. She looks up, finding it very disturbing: Thea's own face twisted with that stretched-out menacing grin. She cackles.

"Nighty-night Super-Softie!", Harley said, tossing the kryptonite towards the spot beside Kara's face, before pressing something that was on her hand, and subsequently leaving the lair.

Kara perceived Harley's exit, as well as the whole lair exploding everywhere. It might have originated from Harley when she pressed the button on what might be a detonator. The lair had a tremor. Explosions bouncing, and the Kryptonian is still in blazes by that rock. She looked at Oliver, noting he is still down. She tries to get up, ignoring the kryptonite shredding her strength to the lowest point; she's still not able to. Pushing herself to drive led to her crawling over to Oliver's side.

With explosions growing destructive, the entire lair's ceilings begin to collapse. Debris smashing vigilante equipment, mannequin used by suits, computers, and other things.

Though Kara is severely weakened by kryptonite, she wasn't willing to let Oliver die even if it mean sacrificing her life for his. She enclosed herself as a shield over Oliver, making sure he lives through.

A/N: The whole thing about Supergirl and Green Arrow being a couple. Well I shipped these two since watching that CW Arrowverse Crossover 'Crisis on Earth-X' where in Universe Earth-X that's where Oliver and Kara of that earth married. So that was what made me ship them.

The name 'Starling National City' doesn't exist in DC Comics. It's rather an amalgam of Starling City and National City. Starling City is the name from the CW series 'Arrow', which was later renamed into 'Star City' in the fourth season of that series.

I wanted Thea Queen to exist in this continuity as I liked that character, especially as Oliver Queen's supportive sister.

Regarding Harley's apparent death, that will be more explore in a different story.

The idea of Thea Queen possessed was kind of conceptually taken from the comic 'Batman: Gotham Knights' on issue 22.