Disclaimer: I don't own Legends of Tomorrow or the Flash

Another spin off from my Brave New World series, this one a Miniseries that continued the story began for the Legends in 'Legends Meet the knight'

Basically that story established a new direction for the Legends and the Arrowverse as a whole in the middle of legends season 2. This Miniseries sees the split Legends meet the Barry Allen of Earth 0 (the main comic continuity) and head in the new directions they'll be in in future stories I tell in the Arrowverse.

Each chapter covers a different member of the Legends, hope you all enjoy.

Brave New World: The Legend of Yesterday

My name is Ray Palmer, last year, a former time master named Rip Hunter, recruited a team of heroes and villains to save the world, and we did. But in the process, we learnt more about the past and the future than we should. Visitors from another Earth have set us all on a new path. We may not be a team anymore, but we're still Legends.

Last time on Legends and the Flash

Bruce Wayne(Earth 0): What Barry did, Flashpoint, it was part of history, it was supposed to happen.

Gideon: Of course Mr Wayne, I have already received the necessary historical information required, Amaya Jiwe will return to 1942, whilst Ray Palmer, Martin Stein, Jefferson Jackson and Nathan Heywood will return to 2017 in preparation for the event history will call 'the crisis'.

Martin Stein: Why send us back to 2017 though?

Bruce Wayne(Earth 0): Because that message from the future Barry, it wasn't concerning the Dominators, there is a threat even worse than them coming, and 2017 is when the preparation for this war starts.

Speed Force?: Barry isn't going to hell, but like all runners must eventually, he has reached his finish line.

?: He can't go, because that's not how the force works. I'm the man who created the Speed force, Barry Allen!

?: I apologise Mr Darhk, Mr Merlyn, Professor Thawne.

Eobard Thawne: I recognise you from my history, a pleasure to meet you, President Luthor.

Mick: Allen, what is it with you and time travel.

Barry Allen (future): There's not enough time, every second counts Sara, every second.

Chapter 1: The Atom

I remember when I was a kid, watching science fiction movies, reading books. Star Wars, Twenty Thousand leagues under the sea. The concept of exploring new worlds, the idea that we weren't alone in the universe appealed to me. One could say it was my dream, and then science fiction turned into science fact, dreams were torn down for reality. And reality could be cruel.

(two years ago)

"Anna, Anna, oh god no," even though Ray Palmer had a broken leg, it was nothing compared to the pain welling up inside of him.

Cradling the woman he loved in his arms, watching Slade Wilson's men just walk away after having broken her neck. Ray was a man of science, but on this day, he was praying for it not be true. Praying that it was a nightmare, that he was going to marry Anna, that they would be all right.

That put me on the path I'm walking now. A path that showed me a new reality. Science fiction, is science fact.

The Dominator roared, firing energy blasts from the device on his wrist. Ray was behind the cover of a sign, ducking his head as the blasts penetrated it. He rolled onto a rooftop, looking over damage to his suit.

"You're cutting it a little close Ray," Felicity Smoak said, working from the Arrow cave and monitoring the mission.

"My blasters were damaged, but I think I might be able to knock him out," Ray said.

"You won't be able to get close enough Ray, you're too big a target," said Oliver Queen, leaning over Felicity's shoulder.

"What if I was a smaller target?" Ray asked.

Felicity and Oliver exchanged confused glances. The Dominator crashed through the sign and Ray pushed the button on his wrist gauntlet. To the Dominator it seemed as if he had disappeared. In reality however, he had gotten smaller, the size of a nail. Jumping between the bits of debris still falling, Ray pulled his fist back, preparing to increase his size as he threw his punch. But it was delayed, he was still tiny when he punched the Dominator, throwing it further back than Ray knew he could at full size. When Ray grew back, he looked at the Dominator on the edge of the building, unconscious and defeated.

"Wow," he muttered.

Central city-Star Labs

Ray pulled up to the famous building in his car. Just a week ago he had been here, helping team Flash stop Savitar and the Reverse Flash. Checking his coat pockets, he felt his shrunk Atom suit. A few years ago, back when Barry was unknowingly mentored by Thawne, Ray had come to Star Labs for their help. His suit wasn't perfect then, it still wasn't perfect, yet it was still a good enough innovation to impress 'Harrison Wells'. The Earth 2 Harry had an altogether different attitude when it came to the Atom.

"It's useless!"

Ray raised his eyebrows at what the man said. Harry had taken all but a few seconds to look at the suit before giving it back to Ray.

"It was good enough when we were fighting Savage," Ray retorted.

"But it's prone to breaking right?" Harry smirked as Ray sheepishly nodded his head.

"But it isn't like it doesn't work altogether," Ray said.

"Hey Ray," Cisco said as he walked into the lab, carrying with him a bag from big belly burger.

"Cisco, I'm glad there's someone here who appreciates the engineering of the suit," Ray smiled, but dropped it when he saw the sheepish look on Cisco's face.

"Actually, whatever Harry's critique about the suit, I may have to agree with it," he said.

"What?"

"I get the idea is to make it more powerful, but it's too bulky, the whole armour look is so 90's, it just feels like you're ripping someone off," Cisco explained.

"Now that Cisco has given you the pop culture side of it, I'll explain the science, the dwarf star alloy you've used to design the suit is supposed to be light, but you've designed the suit to be as bulky as it can be. You've crammed some unnecessary tech in there, the plasma blasters, the flight rockets, the strength enhancement servos, the growth particles," Harry explained.

"It's kind of my thing now, besides I made all of that tech small so that I could put it in the armour," Ray said.

"Yeah Ray, but the tech is still over lapping, that's why you're suit can be buggy," Cisco said.

Harry nodded, both in agreement and approval of Cisco's more scientific approach to the suit. He looked at the younger man as he took out a shake.

"Don't make the slurping sound," Harry said. "Don't make the..."

There was a smug look in Cisco's eyes as he began sucking the straw. Ray looked between the two men.

"Oh I get it, this is like your thing right, concealing a father son respect for one another by annoying each other," Ray said and Cisco proceeded to choke slightly on his shake.

"No way, definitely not a father son type relationship...not this time," Cisco muttered.

"Anyway I just wanted your opinions, thanks," Ray said as he began to walk away.

As he did though he bumped shoulders with a blonde haired man. He was someone he didn't recognise, which was hard considering the Star Labs stuff was pretty much just three people. In the process of bumping into him, he dropped the suit. The blonde haired man picked it up, looked it over and then raised his finger.

"Ooooh, this is the Atom suit...why does it look like it's ripping off Iron man?" he asked.

"That's who it is!" Cisco clicked his fingers, having suddenly realised it.

"Ray Palmer, nice to meet you," Ray said, offering the man his hand to shake.

"Ray huh, you kind of look more like a Clark," the blonde haired man chuckled, but stopped when he saw the confused looks on their faces. "Barry Allen!"

Ray blinked in confusion and both Harry and Cisco rolled their eyes.

"He's an alternate version of Barry, but he doesn't look like our Barry, why are you here other Barry?"

"I just finished my work interview, thank Felicity for the fake references when you next see her. So you're Ray Palmer?" Barry asked looking at Ray.

"Let me guess, your Ray Palmer looks different," Ray smiled as Barry nodded his head. "It's fascinating, what brings you to our world?"

"Same thing that brought Bruce and Hal here!"

"Oh so you're from that Bruce's world, incredible, so has your world faced a crisis yet?" Ray asked.

"A crisis, we tend to have one every two or three years, sometimes we just go from one to another...not that that could happen here," Barry said quickly, seeing the horrified looks on their faces. "So what are you doing here Ray?" he asked, changing the subject.

"Oh I was looking for some help for my suit, but everyone seems to be a critic at the moment," Ray said.

"You know, I worked with my Ray a lot, I could probably give you a few pointers," Barry offered.

"All right, we'll just need some lab space!"

"Yes, take the speed lab please, anything to distract you," Cisco said, pointing at Barry. "From your ridiculous idea of getting yourself struck by lightning."

"What's that about?" Ray asked as he and Barry walked away.

"Kind of what you heard actually, but a lot more to it than that, anyway first thing I was thinking of, lose the whole armour thing...too nineties comic book you know?"

Science is my passion, my whole world now with Anna gone. Part of me has always been tied to two things. A dream I had when I was a kid, a wonderful dream. Science Fiction-becoming science fact.

"No way, that small?" Ray asked, his voice filled with wonder.

"Skin tight, no bulky plates, not even padding underneath the suit, because my Atom didn't need armour, he was the hero you couldn't crush, someone who literally could shrink to the size of atoms," Barry explained, looking over the blue prints of Ray's suit.

The two men had spent less time on science and more time on stories of Barry's Ray Palmer. Barry told him of the amazing things he could do with the size alteration alone. The Ray Palmer of Earth 0/New Earth was never someone who had to increase his size.

"Because he..."

"Retains his strength when he's shrunk, I know, I learnt that recently," Ray finished Barry's sentence, but the old speedster's eyes became serious as he looked at Ray.

"But you need to be extremely careful when you do it Ray, hit someone too hard, move towards them too fast and you'll be like a bullet through their skull, or their organs," Barry stood up and referred to the marker board, filled with diagrams and drawings of atoms and even new designs for the suit. "My Atom had a hundred percent control over his body on a molecular level, the shrinking is just the gateway to other applications, mass control, to be as light as a feather, or as hard as concrete. It isn't just the suit Ray, it's the man too, you need to know the feeling of your abilities, which is something I just can't teach you. I can make you aware of what you can do, but you need to train and practice. One thing I can teach you is how to properly throw a punch!"

"Properly throw a punch?" Ray raised his eyebrows sceptically.

"People with super strength, speedsters, even someone whose shrank yet retains their original mass, have to know how to properly pull their punches. Say for example your Supergirl..."

"Actually, she's from Earth 38," Ray said.

"Whatever, unless she's facing someone who has super strength too, she can't hit someone with a serious punch," Barry explained.

"Of course!"

"Similarly Barry and I (that felt strange saying) have to pull our punches because we build up velocity with our speed, it's about timing Ray, that split second between a punch that can knock out or injure a person."

Ray was eager to learn, his passion for science and optimism was just like Barry's Ray. But Barry could see in Ray's eyes the same pain his Ray felt, when Jean Loring killed Sue Dibny. Something happened to Ray, something that made him feel small when he was at the highest point of his life. But Ray hid that pain well, as well as any other man who wore a mask.

"So your Ray could move through phone cables?" Ray asked as he and Barry made their way to the main lab

"He could ride on the Photon signals, someone actually had to be using the phone for it to work," Barry elaborated. "Now we've talked about this for the past few hours now, let's just have a break!"

Ray looked towards team Flash. Iris and Joe were at the consoles, playing the role of tech support.

"What's going on?" Barry asked.

"Prison transport from Iron heights was hit, Caitlin and Cisco are going with Wally for back up," Iris said.

"Who's the prisoner?" Ray asked.

"Justin Ballantine, he's a nobody but the transport was hit pretty hard," Joe said.

"Where have I heard that name before?" Barry put a hand to his chin as he thought.

Ray focused on the CCTV footage and narrowed his eyes in fury when he saw who was pulling one of the prison guards out of the truck. His armour, straps with guns and knives on them. The sword on his back and the mask on his face. It had a ribbon on the back of it, waving about with the wind. His mask and armour was more menacing than it had been the last time. But the colour of the armour alone identified him to Ray, especially the mask. One side black with no eye, the other side orange.

"Slade!" Ray seethed.

"Deathstroke, oh crap, no offence but Wally's going to need a lot more than Vibe and Ice to help him," Barry said.

"She goes by Killer Frost, but I wouldn't worry about them, Wilson doesn't have his Mirakuru enhancements anymore," Iris said.

"But he's still one of the deadliest soldiers who ever lived...unless he's different in this world...maybe he is...hopefully," Barry muttered.

"Tell them I'm on my way," Ray said.

He ran away, making his way to his lab.

At the prison transport, Slade Wilson in his new armour, slammed his head into the driver's. Fatalities were unnecessary, unless someone pushed him to it. The driver was old, a tired man looking for an easy pension. But Slade put him down just to be on the safe side, and to keep him from being tempted to try something stupid. He made his way over to the back of the truck, removing from his belt an explosive that would blow the lock. As he began activating it, he looked over his shoulder, seeing the distortion that he had studied. The distortion caused by a breach. Drawing his sword, Slade threw the explosive. The breach appeared and the device blew up as Caitlin and Cisco came through it. It burnt part of Caitlin's face, enough to affect how her hair would grow on one side. Cisco was luckily, he was merely knocked back by the explosion.

"Caitlin," Cisco whispered.

"Oh my god," Iris gasped.

Slade put his sword underneath his armpit, sword pointed behind his back. Another second passed and Wally was there, the blade piercing his shoulder. Deathstroke withdrew the blade, and as Kid Flash convulsed in pain, he proceeded to elbow the young man in the back of the head.

"Okay, he's definitely like my Deathstroke," Barry commented, seeing the timing and efficiency that Slade had used to incapacitate people much more powerful than him.

Deathstroke rushed towards Cisco, grabbing his hands and redirecting his sonic blasts, ripping open the prison transport. He head butted him, breaking Cisco's glasses. Then he proceeded to break his arm and put him into a choke hold.

"Sorry about your friend, maybe next time you'll try a safer distance to teleport to," Slade whispered into Cisco's ear before slamming him head first into the ground.

"SLADE!" a voice yelled from above.

Deathstroke looked up, just as Atom slammed into the ground. Ray glared at the mercenary with every bit of hatred he had.

"Last I heard of you, you helped Oliver rescue his son, what are you doing now?" Ray demanded, firing his energy blasts at Slade.

Much to his shock however, Slade's armour absorbed the blasts.

"A man still has to earn a living," Slade said.

"Then go work at big belly burger," Ray retorted.

"The kid may be a speedster Palmer, but he'll still need a hospital, the girl will get an infection too if the burns aren't treated!"

"The old, distract the hero so you can escape tactic, I don't think so Slade, this is personal," Ray attempted to punch Slade again and again, but Slade was too quick.

Ray threw another punch and Slade ducked, pulling on his hand and throwing Ray over his shoulder.

"Ray, you're throwing too hard a punch, he's using the momentum against you. And if you actually get lucky enough to hit him, you could kill him," Barry said, barging past Iris on the support console.

"So what?" Ray snarled.

He got up off of the floor, firing his energy blasts point blank into Slade's chest. But much to team Flash's shock, Slade took the brunt of the attack with a mere flinch. He swung his sword, cutting Ray's wrist gauntlets. His blasters sparked, useless as he attempted to fire again. Slade was about to punch Ray, when the blue and red hero suddenly disappeared. The masked mercenary though wasn't fooled so easily, he was well aware of Ray's shrinking abilities. Much to Ray's shock, Slade could see him. He dodged Slade's sword swipes, flying towards Slade's mask.

"Ray, shrink more, you can take Slade down by attacking his brain directly," Barry said.

"Too easy, it has to be this way," Ray said.

"What?" Barry blinked in confusion.

Ray slammed his fist into Slade's, throwing him back with such force that it knocked his helmet off of his head. Slade fell to the ground just as Ray returned to his original size. Iris and Joe shared Barry's earlier confusion, looking at Slade Wilson. His hair, even his beard had turned chalk white.

"Why is his hair that colour?" Iris asked.

"His hair wasn't that colour before?" Barry asked.

Ray took off his helmet, looking down at the downed mercenary.

"Anna Loring, she was my fiancé, the love of my life, when you attacked Star City, your men broke her neck. She had nothing to do with your vendetta against Oliver, her death is on your hands. I want to kill you, so badly, but I'm not a murderer," Ray lowered his head and sighed, part defeated, part at peace.

He gasped as Slade opened his hand, and a flash bang rolled out of it. The bang distorted Ray's vision and hearing. He stumbled back, then felt a searing pain in his chest.

"NO!" he heard Barry yelled over the radio. "Not again!"

His vision was still shaky as he looked at Slade. The mercenary was holding his sword with both hands, the blade inside Ray's chest.

"For what it's worth, I'm sorry for her death, I wasn't in my right mind then," he narrowed his eye, his voice growing darker and fierce. "But I am now, get in my way again and I won't miss your heart next time!"

He pulled the blade out and let Ray fall to the ground. After putting on his mask, Slade returned to the prison transport. He grabbed Ballantine, a dark haired man whose face remained passive as Slade guided him into the desert. Slade put a hand to his ear.

"Ready for extraction," he said.

Ray looked towards Slade, seeing the light pass over him and his prisoner. When the light faded, Wilson and Ballantine were gone. He heard Cisco and Wally yelling, he could tell they were yelling but he just didn't know what. His body felt numb and his breathing became laboured.

"Anna," Ray whispered, before he closed his eyes.

Laying there, dying, I look back on my life. A kid with dreams of exploring new worlds. A scientist who wanted to change his world. A man who wanted to be with the woman he loved. A hero who wanted justice. A loser who wanted to become a legend. My failures, my loves pass before my eyes. Felicity and Kendra, their hearts were always meant for others. Then I see Anna, smiling at me. I've never had much belief in god, I'm a man of science after all. But the thought of being with her again makes me happy.

Then I see her shake her head and frown. The way she would when I was putting work before us. And paradoxically, she would still frown like that when I tried to put my work off for her. She accepted my passions, she wanted me to be who I wanted to be. Felicity said that she wouldn't want me to die, what loved one would? She wanted me to be who I wanted to be. She wanted me to live for my dreams.

Ray heard the heart monitor as he woke up. He looked down, seeing the bandages on his chest and Felicity sitting in the chair beside his bed.

"How are the others?" Ray asked.

Felicity woke up with a start, looking at Ray in both shock and relief.

"Oh my god, thank goodness, we thought we lost you," she said.

"How are the others?" Ray repeated the question.

"Cisco broke his arm, and he's been nursing a concussion, Caitlin's powers protected her skin, but not so much her hair, and Wally healed faster than all of you," Oliver explained, revealing himself to be standing at the doorway.

"That's good, that's very good, and the other Barry?"

"Still here, still trying to kill himself," Felicity sighed.

"What do you mean?"

"He has this idea that if he lets himself get struck by the lightning from the speed force storms affecting Central city then he'll get his speed back," Felicity explained.

"I believe him," Ray said.

"Me too strangely," Oliver said.

"Why?" Felicity asked.

"Because I've always believed that that lightning chose Barry, that what happened to him happened for a reason," Oliver explained.

"And I've begun to believe that there is a rational explanation for everything, it's just up to us to find it. So rather than judge Barry, I'm gonna help him," Ray said.

"Fine, but please, don't let him do what he's planning, find another way to help him," Felicity urged the man she used to date.

Ray nodded his head, still smiling.

"Can I talk to Oliver alone for a moment?" he asked.

"Sure, talk to you later Ray," Felicity kissed him on the cheek and then walked out of the room, leaving the Atom and the Green Arrow alone.

"If this is about Slade..."

"I'm done," Ray suddenly said, interrupting Oliver.

"Done? What do you mean Ray?" he asked.

"I've had some time to think about it, and my fight with Slade proved it. This, the whole Atom suit, it wasn't about what it should have been. I claimed to be using the dwarf star alloy to change the world, but it was for revenge, that's all," Ray explained.

"You wouldn't be the first person to set out on the right path for the wrong reasons Ray, you've done so much good," Oliver said, shocked when Ray chuckled.

"I'm not diminishing what I've done Oliver, I accomplished good things and I'll never regret that. But when I fought Slade I realised that, Felicity was right, I was killing myself and that isn't what Anna would have wanted. Don't get me wrong, this crisis that's coming, it's going to need the Atom and I'll be ready to help you guys out. But everything else, the patrols, the crime bosses, that's not my world anymore."

"What will you do in the mean time?" Oliver asked.

"I'm going to focus on research, on doing what I've always dreamed of doing, I've got some great ideas for the new direction I'm gonna go on," Ray explained.

"Well I can tell you've thought about this, and for what's it's worth I think you're doing the right thing. And you don't need my approval on this Ray, I'm not your squad leader," Oliver explained.

"Are we friends?" Ray asked.

"I suppose we are, good luck Ray," a rare smile crossed Oliver's face as he walked out of the door.

In the following months, Ray recovered, settled the legal matters of his 'death'.

"Today I'm announcing that I will be stepping down as owner and CEO of Palmer Tech, and giving my majority shares to my friend Felicity Smoak," Ray called a press conference to announce his intentions.

Ray continued to look into a new direction for his Atom suit. Once he'd completed his adjustments, he returned to Star labs, where a sceptical Harry and Cisco waited, the latter with his arm in a cast.

"A belt, you traded in the armour, for a belt?" Cisco asked.

As Ray chuckled, Barry walked into the room and took a look at the red belt across Ray's waist.

"Oh, you're following my idea?" he asked.

"Yep, Cisco, Harry, Barry, you three will officially be the first to witness the debut of the all new, and improved Atom," Ray grinned as he pushed the Atom symbol on his belt.

It began to glow red, suddenly, blue and red fabric began to spread across Ray's body. The red covered his legs and chest, with blue fabric covering his feet in the form of boots, then across his hands as gloves. Cisco stepped back, gasping in amazement as the fabric covered Ray's shoulders. It ran up his neck, beginning to surround his head, covering everything except his mouth and eyes. Red lights briefly glowed across his outfit, and the Atom symbol appeared on his forehead.

"Now that is the Atom," Barry said.

"Is that..."Harry began.

"Nanotech," Cisco said, whistling and staring at the suit. "But what about the blasters and the rockets?"

"I'm losing them, from now on the Atom is a hero of science, you don't think it's too much right, it feels a little tight on the crotch, might need some adjustments," Ray explained, the cowl part of his costume disappearing as he spoke.

"This is more like it Ray, good luck to you," Barry slapped Ray's shoulder as he walked away.

"Hey Barry, those things you needed, I managed to find them," Ray said and Barry nodded, putting his hands in his pockets and seemingly parting ways with this universe's Atom.

A few months later, Ray had finally finished setting up his lab at Ivy town university. He was video conferencing with Felicity, and at the same time looking over a smaller version of his belt.

"Well lab assistants have been scarce, there is one application I'm particularly interested in, this Ryan Choi kid," Ray said.

"Well I'm glad you're doing fine Ray, I managed to piece together some of the CCTV footage, Harry theorises some kind of teleportation, but obviously very different from a breach, it seems to involve actual manipulation of the subjects atoms, so in time we might be able to track where Slade went," Felicity explained.

"Send the date over to me and I'll have a look, in the mean time I need to get back to my own research, found something pretty big...well I suppose small is a better term," Ray laughed and Felicity narrowed her eyes in confusion.

"What are you talking about Ray?" she asked.

"Well you see during my experiments with the size changing belt I was able to go subatomic, it was during these tests I stumbled upon something that puts the multiverse discovery to shame," Ray explained.

"You don't mean..."Felicity gasped, the part of her that was a scientist amazed.

"An entire new world, I think I'll call it 'the Microverse'."

Pacific Coast-Unknown Yacht

When Ballantine and Slade reappeared, they had appeared on a Yacht, on a pad usually reserved for a helicopter. Ballantine looked at his surroundings, partly in confusion and another part in happiness. He took a deep breath, cherishing his new freedom. Then Slade shoved him, forcing him to walk to the lower part of the boat. There his employer waited, his sleeves rolled up, making a cocktail at his mini bar.

"Good to finally meet you Mr Ballantine, my assistant will show you to a shower and a change of clothes, we'll discuss our business later, in the mean time I'd like to speak with Mr Wilson for a moment," the man explained.

Ballantine nodded his head, walking with the employer's assistant to the back of the ship. Slade stood as the man sat down.

"Thank you for the assistance in this matter Mr Wilson, did the armour work as we suspected?" the man asked.

"Better, is my payment ready?" Slade demanded.

"The money has been wired to your account, and I'm emailing the location to your phone. I hope this doesn't conclude our relationship Mr Wilson, you're a resource I think we're solely going to need!"

"You better not be wasting my time Luthor!"

"Oh I value my life far too much to make that mistake, by all means, settle your affairs, and at least think about the future," Lex Luthor smiled as he sipped from his drink.

Slade checked his phone, the payment was done. He also received the locations, including current photos of his next missions. A blonde haired boy in a hospital bed, heavy bandaging across his neck and photo of a part Vietnamese girl. Closing his phone, he turned away from Lex, tempted to just walk away from the man forever. But then a mix of curiosity, greed and just plain boredom got the better of him.

"What's the job Mr Luthor, and the payment?" he asked.

"The job Mr Wilson, is turning the tide and restoring the balance of power to those whom truly hold it. These vigilantes, the Arrows, the Flashes, and all the others coming out of the wood work. They're getting organised, I think it's about time we get organised too," Lex Luthor grinned and Slade tilted his head, intrigued by the idea.

"Have you ever been to Gotham city Mr Wilson?"

Next Chapter 2: Firestorm

Hope everyone enjoyed the first chapter.

Slade's armour was like the new one in the Justice League movie. And this Lex Luthor I'm imagining being played by Michael Rosenbaum, famous for his great portrayal of Lex in Smallville (also coincidentally a Flash himself).

Make create a spinoff featuring Deathstroke, providing explanations for his new armour, his new hair colour and the new mission he's gotten intel from Luthor for.