AN: Hey guys, AuraStormMaster here. I know, yet another story. This one however, isn't really my fault. This one I had started during the mid-season finale of The Flash, but I soon lost interest. Recently though, I found the idea becoming much more appealing once again.
Also, while this is a Harry Potter and the Avengers crossover, The Flash is another key element to this fic. Think of each chapter being the equivalent to that of a TV episode, and each story arc as a volume of the comics.
Anyway, on with the show!

Disclaimer I don't own Harry Potter, The Flash or The Avengers, all properties belong to JK Rowling, DC Comics and Marvel respectively.

Timelines (AU):

HP – Post OotP
Avengers – Post TWS
Year – 2015

Key

"Hey" – Speech
"Hey" – Phone & Radio Speech/Telepathy
'Hey' – Thoughts
"Hey" – Spells
"Hey" – Vibration Speech

Emerald Flash – Volume 1: Learning to Run

Issue 1: Birth of a Legend - Lightning Strikes (Part 1)

My name is Harry Potter, and I am a teenage wizard who is prophesised to save the Wizarding World. To the rest of the world, I am also known as the Fastest Man Alive. Thanks to an accidental collision of lightning and potions, I was given the gift of incredible speed.

Dust clouds, ash and rubble filled the once busy streets of Godric's Hollow as the sounds of explosions ripple through the air. Amongst the burning buildings and towering piles of rubble, a streak of yellow lightning zigzagged its way through the wreckage, occasionally leaping over clumps of twisted metal and busted stone. Coming to a stop, the lightning dispersed and revealed a solitary figure, who lent against one of the few untouched buildings in the city.

A crimson body-suit covered the figure from head-to-toe, with golden lightning designs snaking around his wrists, chest and waist. Several gold lines trailed along his arms, legs and chest, while a crimson cowl masked his face, only the figure's eyes and mouth could be seen. A white, gold-rimmed circle was displayed on the, obviously, male figure's chest. In the centre of the circle was a yellow-gold lightning bolt insignia. Crimson gloves and boots covered the remaining parts of the speedster's body.

The suit itself was rather beaten, rips and tears covered the male's limbs while a massive tear could be seen leading from the right shoulder to the figure's left hip. Emerald eyes scanned the area frantically before the crimson-clad figure vanished in another streak of lighting.

I know your probably wondering what the hell is going on here, but in order to understand just what happened, we need to go back a bit. Back to the day it all began: the day I received my powers.

Three Years Previously – Ministry of Magic: Department of Mysteries

"Dammit!" Harry swore, as he was forced to duck under yet another jet of deadly light. Raising his trusty holly wand, he fired off a bolt of scarlet energy in the direction of his opponent, and smiled grimly in satisfaction as the robbed form of a masked Death Eater collapsed to the cold stone floor. Glancing over his shoulder, he sprinted in the direction he had seen Ron and Neville run through, only to collide with a soft body just feet from the door.

"Oof!" Came a feminine cry, causing Harry to stumble back and take in just who he had run into.

"Hermione!" he yelled, happiness swelling up in his heart as he took in the dishevelled appearance of his best friend. Her robes were ripped at the hem while a cut bled slowly just over her right eye. Her normally bushy hair was lank with perspiration and she seemed to be favouring her left side.

"Oh Harry, you're okay!" She squealed, pulling the slightly taller wizard into a backbreaking hug, who wrapped his arms around her just as tightly for a few seconds before pulling back.

"What happened to the others?"

"Ron's down via a bone-breaker, Neville was last seen in the time room with Luna and I have no idea where Ginny is." Hermione rattled off, scanning the room for any active Death Eaters. Harry growled at the thought of the missing students.

"Perfect." He snarled, eyes narrowing in anger as he gripped his wand tightly. "Death Eaters are running about and Ginny decides to go off on her own. Now what the hell are we-"

"POTTER!" Roared a familiar voice, causing the two teens to spin in the direction of a panting, red-faced Lucius Malfoy.

"SECTUMSEMPRA!" Bellowed the older blonde, slashing his wand in the direction of the two Gryffindors.

"Get down!" Harry yelled, diving to the ground and yanking his brunette friend with him. A jet of midnight-black energy flew over their heads and slammed into the wall behind them, gouging a foot-thick scar into the wall. Upon seeing the damage, Harry snarled in rage towards the elder Malfoy.

"Incedius Maximus!" He cried, conjuring basketball-sized balls of fire and hurling them at his foe. Lucius leapt to the side, tossing his robes away as the hem caught alight. Snapping his wand up, he fired of a rapid chain of Bone Breakers, Blood Boiling and Killing curses. The two teens ducked, dove and ran from the room, the various curse slamming into walls and furniture.

"In here!" Harry yelled, pointing to a glossy black door to their immediate left. Grabbing the brunette witch's hand, he tugged her in the direction of the door and jabbed his wand forward.

"Alohamora!"

The obsidian door burst open with a small 'creak' as the pair hurtled through the now open doorway. As soon as they were inside, Hermione pointed her own vinewood wand at the open door.

"Colloportus." She cried, flicking her wrist slightly, causing the door to slam shut with a slight squelching sound. With a sigh of relief, the two teens rested their backs upon the now sealed door. As they caught their breath, the Gryffindor duo eyed their surroundings in confusion.

The room itself was similar in design to the Hall of Prophecy, except this room's shelves were lined with many different vials of various potions. Some contents of the vials were murky in light, bright in colour or practically shone with the magic infused within the liquids.

"What is this place?" asked Harry, eyeing their surrounding warily. Something about this room made him feel...edgy.

"Look at all these vials!" Hermione gasped, eyes glittering at the sight of the shimmering crystal containers. "Some of these potions aren't even taught at Hogwarts."

"For good reason I suppose." Harry muttered, eyes scanning the various gaps within the rows, alert in case of a surprise attack from any more Death Eaters.

"We should go, keep your wand ready."

With one last glance at the door they had entered, the pair began their journey into the depths of the room, their wands lit ahead of them as their heads scanned each and every row they passed. After a few minutes, Hermione suddenly froze.

"What was that?"

Harry had frozen too, as a soft 'click' had reverberated throughout the room, alerting the pair that they were no longer alone. Hermione began to open her mouth, but Harry quickly silenced her with a look, all the while gripping his wand tightly. The silence in the room was both deafening yet eerie as the pair scanned their surroundings for any sign of their fellow inhabitants.

"Crucio!"

Hermione screamed as the Torture curse slammed into her exposed back, sending her crashing to the floor as she convulsed violently. With a snarl, Harry fired off stunner after stunner in every direction, causing their attacker to release their hold on the Unforgivable curse. As Hermione recovered from the assault, Harry aimed his wand skyward.

"Lumos Maxima!" He bellowed, flooding the large room with an insanely bright light. With a cry of pain, Lucius Malfoy staggered from his hiding place, allowing Harry a perfect opportunity.

"Impedimenta!" Harry yelled, firing off a bolt of cobalt energy in the direction of the blinded blonde, who was knocked off his feet by the force of the blow. As Malfoy struggled to recover, Harry turned to his downed friend.

"Hermione," He murmured, helping the brunette witch to her feet as she severely trembled.

They had just begun to make their escape, when Harry was knocked aside by a blast of wind, sending him crashing into the side of one of the many rows of potions. The vials wobbled slightly, but managed to remain safely on their shelves. As he leapt to his feet, a little dizzy from the collision, he caught sight of Malfoy storming his way down the aisle, a insane snarl twisting his regal features as he aimed his wand at the still shaking Hermione.

"I'm done playing with school children. FULGUR AETERNAM!" Malfoy screamed, firing a powerful bolt of lightning at the stunned witch.

Time seemed to slow down for Harry as he ran towards his frozen friend, all the while the lightning bolt crept closer and closer until...

"Hermi-ARRGH!" Harry screamed, shoving his friend out of the way only to be struck in the side by the electrical surge. Hermione screamed as the raven-haired wizard was blasted towards one of the many racks of potions that filled the room. As he impacted against the shelves, the vials spilt their unknown contents all over the twitching wizard, who unconsciously unleashed a blast of magic which sent the rest of the occupants crashing to the ground.

"Harry..." Hermione murmured, before succumbing to the gentle hold of Morpheus' realm.

As the three magic-users lay upon the cold stone floor, none of them knew just how important the previous event was to the world, as a small trail of electricity briefly flashed upon the side of Harry's face.

~Emerald Flash~

Beep...beep...beep...

Hermione let out a sigh as she sat beside the comatose form of her best friend. The Heart Monitor charm beeped away in time with his heart, while this had brought her comfort that her friend was still within the realm of the living, there had been moments when his heart rate flat-lined, but he was always resuscitated in time.

"Oh Harry..." she murmured, lightly running her hands through his raven locks. To her dismay, Harry just lay there, unresponsive to the rest of the world. As she turned to look out of the nearby window, all of a sudden, the unconscious Potter heir suddenly sat bolt upright with a deep gasp.

"AH!" She yelped, startled by the sudden movement. Harry just stared around the room, taking deep panting breaths in time with his heart beat. As he began to regain his bearings, his vision was sudden obscured by a mass of bushy brown hair.

"Harry!" cried Hermione, hugging him tightly as tears began to fall from her cinnamon orbs. With a small smile, the emerald-eyed wizard wrapped his arms around the crying girl's small waist, returning the action in kind.

"Hey there Mione, you're acting like someone died on us."

No sooner had his last few words left his mouth, did Hermione suddenly stiffen and her grip slackened slightly. Eyes narrowing, Harry pulled back to look into the girls' wide eyes.

"Hermione..." He trailed off, his tone questioning. Taking a second to wipe her eyes, Hermione gave her best friend of five years a worried stare.

"It's just that...oh Harry. Technically, you died...several times."

Silence.

"...what?" Harry said stupidly, blinking rapidly in surprise. Hermione couldn't help the small smile that crept up her lips at the slightly lost look on his face.

"You need to understand, you've been in a nine week long coma. And, several times in fact, your heart stopped beating. Only to begin beating again a few minutes later."

Harry just stared at her in shock, eyes remaining unblinking as many different thoughts raced through his mind. It took him a few minutes until he realised that Hermione was still talking.

"Sorry Hermione, my mind was in a completely other place there. What were you saying?"

Hermione gave him an exasperated, yet fond smile as she rolled her eyes.

"What I was saying, was that there were both victories and losses in the battle."

"Tell me the losses first, if you don't mind."

Hermione offered him a look of understanding as she reached out and grasped his right hand.

"Ron was...attacked by a strange brain. The last I saw, it was still attached to his arm. Ginny had both of her legs shattered, and Neville suffered the minor loss of his wand. However..."

As she trailed off, Harry immediately knew that something bad had happened.

"Hermione, what else happened?"

Taking a deep, shuddering breath, Hermione locked eyes with her raven-haired friend. Harry was worried to see that tears had begun to leak from her eyes once again.

"Harry...Mr Weasley was killed. By Bellatrix Lestrange."

~Emerald Flash~

Harry sat in his new room, in the recently rebuilt Potter cottage. A lot had happened in the last few weeks.

He and his friends had attempted a rescue mission to the Ministry, only for it to go horribly wrong. He had fallen into a coma, Ginny had been paralysed, Ron's status was still unknown and poor Mr Weasley was killed. However, not everything had turned out so bad.

All the Death Eaters there that night had been rounded up and sent off to Azkaban, including the surprise appearance of one Mr Peter Pettigrew, resulting in the search for Sirius Black to be discontinued.

Harry gave a small smile at the thought of his godfather. Currently, the head of the Black family was at Gringotts dealing with some legal matters, Harry had drifted off at that point in his and Sirius's conversation.

Growl

Harry frowned as his stomach began to growl once again. He was completely bemused, as this would have been the THIRD time he had eaten today. Although, now that Harry thought about it, he had noticed an abnormal increase in his dietary intake as of late. Groaning, the young Potter air climbed to his feet and walked to his bedroom door...

...only to walk into his kitchen a second later.

"What the hell!" Harry yelped, shocked at the incredibly sudden change in scenery. Turning, he made to move back into the hallway...only to end up slamming into his front door.

"What's happening to me?" He murmured, his frown deepening as a strange tingling began to race up and down the length of his left arm. Raising said arm, he was horrified to discover that his arm was vibrating at an insanely fast frequency.

Grabbing his front door, he wrenched it open and ran outside.

A huge mistake.

"Whoooooooooaaaaaaaaa!" Harry yelled as he blitzed through the streets of Godric's Hollow. When he finally pulled himself to a stop, he glanced around at his surroundings.

Nothing but fields dominated his eyesight, while his shoes emitted small bursts of smoke due to the high velocity he had been moving at.

"What the hell is going on?" Harry yelled, although no one could respond to his query. Glancing back down the road he had arrived by, an idea slowly began to form in his mind, a grin soon spread across his lips.

"Here goes nothing." He muttered, taking a deep breath as he focused his attention on the road before him. Bracing himself, he was soon hurtling down the road at break-neck speeds once again. Except this time, he had managed to gain control over where he was going.

"WOOOOOOOOOOOOO!" Harry screamed in delight, adrenaline flooding his system as he continued to zip around at insane speeds. After what seemed like hours to Harry, he soon came to a halt back up in his room, having sped back into his house and shutting the door after him.

Panting, he noticed the only flaw of his newly discovered abilities.

"Lucky no one could see me, I guess." He laughed, noticing that thanks to the high amounts of friction he had generated, his shoes and clothes had been burned away.

~Emerald Flash~

Eyeing his magically enhanced Police scanner, Harry tugged on the final parts of his outfit. After recalling the superhero's that starred in the various comic books that Dudley had read in their youth, Harry had decided to try his hand at heroism. Looking in the mirror attached to his bedroom wall, Harry mentally thanked the fact that the Ministry couldn't detect magic thanks to the wards surrounding the house.

After his initial run, Harry had learnt the necessity of learning the friction-less charm that was usually applied to broomsticks, although he had applied it to all of his clothing. Today, Harry had decided that his first superhero costume would consist of a pair of red low-cut converse all-stars, blue jeans and a red hooded jumper.

"A quick patrol of the city, and then back here to meet Hermione." He muttered, grabbing the hood of his jumper and pulling it over his head.

"What could go wrong?"

"All units, Town Hall has been taken over by a gang of criminals and all occupants are currently being held hostage."

"Me and my big mouth." Harry groaned, placing a red domino mask over his eyes, all the while mentally thanking Sirius for letting him correct his eyesight earlier in the summer.

"Right then, this'll be a piece of cake."

And with one last grin into the mirror, Harry blasted out of his house and ran in the direction of the Town Hall.

Twenty minutes later

Grunting, Harry limped into his room, his left shoulder clutched firmly in his opposite hand.

"Stupid super-speed." He grumbled, gingerly pulling his hood down and kicking off his shoes. With a groan, he sank down on his bed, still clutching at his shoulder.

"Note to self, super-speed and waxed floors do NOT mix. Maybe if I had proper grip, I wouldn't have had so many close calls with those bloody knifes."

Tugging off now ragged jumper, he tossed the bundle of red fabric next to him. Glancing down at his watch, Harry was surprised to see that he had only a few minutes to tidy up before Hermione arrived.

Taking a deep breath, he was soon zipping around the room in a blaze of lightning. With a small whoop, he lay back onto his bed once again, his room now spotless. Merlin, it was good to be-

Cough

Harry shot bolt upright, his head snapping to the direction of his door. Where Hermione stood. Wide eyed.

"Well...bugger me."

AN: And...Cut! . And if anyone is wondering, the costume described at the start of the chapter is a blend of the New 52 (both pre and post-convergence) and the Flash TV show designs.
Little bit of a slow start, but overall I thought it turned out OK. Next chapter will definitely be much faster-paced.
Also, as stated above: each chapter could be compared to that of a single episode on TV. However, consider each story arc like that of the comics, where they are split into volumes.
Chapter 2 is nearly done, so expect that later today. In other news, Mad-Man Reborn should see an update by the end of the week, while SOL' ending should be up later on today as well, tomorrow at the latest. Murder in Metal will receive a new chapter in the coming weeks, while Burning Ice will be put to the back-burner as I begin work on Harrison Quinn: Wizarding Wars (Title work in progress).
Make sure to R&R, Follow and/or Favourite ect.
This is AuraStormMaster, signing off.

OC Spells

Fulgur Aeternam – The Eternal Lighting Spell: The caster gathers all electrical energy in the surrounding area and sends it toward the opponent in the form of a wicked lightning bolt.

The Heart Monitor charm – Monitors a person's heart rate, mostly used my medi-witches and healers.