A saiyan in Equestria?

The final battle has dawned upon Equestria, the supposedly invincible Nightmare Moon is cornered, or is she?

"I'm a goddess! This battle shall decide your fate!" said Nightmare Moon feeling High and Mighty

"Done gloating? You're gonna drag this fight on if you keep talking." said Ato

"Just to make sure, I'll check it's power level." Ato thought, as soon as he tried to get a grasp of her power level, the scouter malfunctioned. "Perfect." he thought

And without hesitation, Nightmare Moon took the first strike, uppercutting him with his hoof, then electrocuting him with magic before he could blink.

Then, Nightmare Moon just moved back slowly, not even putting up a fighting stance. Seeing this as an opening, Ato flew at her and punched her square in the face, when Ato removed his fist from her face, she looked almost bored.

"That tickled." she said knocking Ato away effortlessly, before charging at him to jab him rapidly.

"Dammit, they weren't lying when they said Nightmare Moon was invincible." thought Ato "There has to be a way I can stall for time!" Ato knew that he was going to die if he couldn't find a solution fast enough.

"Think, think, think!" Ato thought to himself, then Ato did the least prideful thing he could do as a saiyan, run, or more accurately, a chase. Ato knew that if he fled, Nightmare Moon would come after him, so it would give him a little bit of time, but not much.

"Hey! Come get me!" taunted Ato, who flew away as fast as possible

"You will not evade me!" cried Nightmare Moon and she gave chase to Ato

She summoned storm clouds in an attempt to strike down Ato, but he was smarter than that to fall for it.

Ato stopped to take a breath, "I think I lost her." said Ato

"Behind you." said Nightmare Moon devilishly

Ato suddenly felt an intense pain in his stomach, and when he looked down, he saw a horn, covered in blood had pierced through his stomach.

"Still not dead? I can help with that." said Nightmare Moon

Within seconds, Ato began seeing holes in his body appearing at an alarming rate. Nightmare Moon was puncturing him like a balloon and he was powerless to stop it.

"Die!Die!Die!Die!Die!Die!" she cackled

At that point all seemed lost, but then a voice cried from afar

"SONIC RAINBOOM!"

In the next second, Nightmare Moon was tackled by a blue blur.

"Hey, I told you that I'd help you when you needed it!" said Dash

"That was a nice surprise, you caught me off guard. But now, both of you are going to die painfully." said Nightmare Moon unfazed

"Twilight and the rest of the gang are gonna be here with the elements of harmony soon, so we need to hold out just a little bit longer!" said Dash

"Got it." said Ato

"Oh and this is from Twilight." Dash tossed a potion over to Ato, he drank it, and he was healed of his wounds.

"Very well, I'll start with you." said Nightmare Moon, and she charged towards Dash with her horn in an impaling position.

"Not this time." said Ato and he intercepted with a strong kick to the jaw, now he could actually make her feel pain with the brink-of-death power boost a saiyan gets, but it wasn't nearly enough power to beat her.

"Grr, you mortals are getting on my nerves, Divine bolt of the heavens! I channel thee!" said Nightmare Moon

Bolts of lightning fell from the heavens, just barely missing RD and Ato.

Even though it seemed RD and Ato had the upper hand/hoof, Nightmare Moon was laughing, just laughing.

"Something funny?" Ato asked, suspicious

"If I can't win this fight, and take over Equestria, then I'll just blow it up! Haahahahahahahhahahaha!" she said maniacally

At that point Ato and Dash noticed that Nightmare Moon was building up enough destructive magic

"You're-YOU'RE INSANE!" cried Dash

"Dash, ignore it, she's too selfish to blow up Luna's body." Honestly, Ato wasn't sure, he had to tell a lie to keep Dash level-headed and focused

"Rainbow Dash, Ato, we're here!"

Twilight had arrived with Fluttershy, Applejack, Rarity, and Pinkie Pie, and they brought the elements of Harmony as well.

"Step back!" yelled Nightmare Moon "One step closer and Ponyville and everyone here blows up!" she threatened

Ato found himself staring at the Elements of Harmony, it felt like something in him was connected in some way to them.

He concentrated hard on them, and he felt something important was supposed to happen.

"Twilight, can I borrow some power from the Elements? I feel like it would be important." said Ato

"How can you be so sure?" she asked

"I've got a gut feeling, just trust me on this one." he said determined

Slowly, Ato began absorbing the strength of the elements of harmony, but something was very strange, the elements had formed a chain of light around him, like some ritual.

Ato's hair stood up and flashed green every few seconds, the planet itself began to tremble.

"Twilight, I think it's working, keep at it!" said Ato

"Okay, I'll try my hardest!" she responded

Suddenly, Ato felt disconnected from reality

"Kindness, Honesty, Loyalty, Generosity, Laughter, and Magic, and one to unite them all: Justice." those words ran through his mind until he had memorized it. When he did, he felt he had returned to reality.

"RAGGHHHHHHHHHH!" Ato felt his body undergo a rapid change, a transformation almost.

His hair stood up, and was now a benevolent light green.

Nightmare Moon was almost ready to release her spell, but she lost concentration when she saw Ato, who looked intimidating and different.

"What are you? You freak!" Nightmare Moon asked

"Me? I am one of the last survivors of a warrior race, I fight for the good of all those around me. I fight to honor my lost people. I'm the one spoken of in legends, the lost hope. I fight those who have turned against the side of good. But most of all, I AM A SUPER SAIYAN, THE ELEMENT OF JUSTICE!" he said with no fear whatsoever

He flew slowly towards Nightmare Moon, staring her down, ready to end the fight.

Nightmare Moon said all the spells she knew to smite him, they were pebbles to him, and he just continued to fly towards her.

Finally when he was in close reach, Nightmare Moon tried once again to stab Ato, he used it as an opening, he grabbed her by the horn, and threw her flying into space.

"Nightmare Moon, you're not going anywhere!" Ato held his right hand over his head, and channeled a combination of magic and ki in it, and put it in one beam to permenately end Nightmare Moon's reign.

"No, No NO!" Nightmare Moon collided with the beam head on, and her spirit was slowly being consumed by it, leaving Luna's mind and body behind.

When Nightmare Moon died, Ato could've sworn he heard Luna say "Thank you."

It was morning when Nightmare Moon was finally vanquished.

"Hey guys, I did it!" Ato reverted back to his normal state and fell unconscious, exhausted from the large amount of ki he had used.

When he woke up, the whole kingdom was there to congratulate his victory

"IT'S THE HERO OF EQUESTRIA!" one pony cried

"THREE CHEERS FOR THE HERO!" another cried

After the ceremony, Ato was approached by Celestia

"Ato, because of your brave actions, I'm going to give you one wish, you can have anything, at all." said Celestia

"Well, I wish that somewhere out there, the saiyan race prospers and grows again, for generations and generations.

THE END.