Rainbow landed outside of the castle, feeling confidant "I'm so awesome I don't need a ring!" she mutters, entering the throne room.

Spike looks up from scrawling something on a large pad, several papers scattered around the table "Hey Rainbow!"

Twilight walks out of the kitchen with tea in her magic "Why am I the one fetching tea?"

Spike rolls his eyes "You're a mage Twilight, you deal in facts and absolutes. I am a genius in the more esoteric pursuits and vectors of knowledge, logic, and reasoning."

Twilight stares at him, surprised "Uh... define 'Esoteric'"

"Esoteric means things and subjects that cannot be reasonably explained by linear logic without a large amount of uncertainty or are too small to be observed with any known or possible means. Basically, parascience." Rainbow says, looking at Spike's notes "Uh... dude? I'm sure that the spatial coefficient isn't supposed to be rounded."

Spike walks over to her and gasps "You're right! This would've spiraled out into complete inaccuracy! Thanks so much Dash!"

Rainbow shrugs "Hey, I just happened to have mistaken weather-based chaos theory class for something about wild weather."

Twilight stares at them both "Spike I can believe being able to maybe comprehend that level of math, but you Rainbow? And Chaos is... unnatural."

Rainbow sighs "I wish I could explain it, but I'm not good at that."

Spike shrugs, writing something "It's basically using biology, physics, statistics, meteorology, and mathematics to explain the inaccuracies and the ability of incredibly random things occuring."

Twilight furrows her brow "Is it 'Confuse Twilight day' or something? First I can't get a straight answer about how the ring and lantern work and now you two are evading my questions. I'm going back to bed."

Spike rolls her eyes "I'll get Derpy to explain it to you tomorrow!"

Twilight grumbles something in response and slams the door shut.

"That's the broom closet." Spike says, not looking up from his papers.

Twilight exits the closet and opens another door, slamming it behind herself.

She huffs over to Spike "Where's my room?"

Spike looks up "At the end of the hall, the one with your cutie mark on the center."

Twilight thanks him and walks away, grumbling.

Rainbow looks around the room "Where's Relok?"

"Said something about practicing with his ring."

Rainbow shoots out of the library and scans the ground looking for him "I knew it was stupid to try to leave him alone... stupid stupid stupid!"

Then a bright flash of green light burst on the horizon "Either that's him, or another lantern..."

Rainbow lands next to Relok "What don't you understand about 'I have to keep an eye on you' don't you understand?"

Relok turns to her, a number of copies holding weapons in their hands lined up in front of him "I am capable of looking after myself."

She shrugs "I'm just following orders, guy. So, what are you doing?"

"I am practicing my constructs." her motions to the solid green copies of himself.

Rainbow stares at the lantern next to the burnt capsule "Do you mind?"

Relok frowns "I do. Don't touch it."

Rainbow glares at him "I meant the pod thingy. I think I can fix it."

He stares at me for a few seconds before nodding "Do not break it."

Rainbow grins and sticks her head into it, a number of dim lights on the circular panels illuminating the inside "Okay... don't touch any red buttons..."

A beep answers her and she covers her face with her hooves "I didn't touch anything!"

A screen in front of me brightens, a blurry figure distorted by static "Green lantern Relok Tag?"

"Uhh... I'm his friend, is that close enough?"

The figure ignores her "There is a yellow lantern in your sector, exercise extreme caution and do not confront it."

Rainbow nods "Yellow guy, don't do anything, be careful, got it!"

The screen dims and Rainbow walks out of the pod and flies onto Relok's back "Big guy, you got orders from your boss."

He turns to her "I did not receive any orders from my rin- AUGH!"

A blast of yellow slams into his torso, knocking him onto his wounded side.

Rainbow takes flight, looking for whatever hit him "What just happened?!"

A tall fish-bird descends from the sky, bright yellow clothing covering its body, a sparking yellow ring on one hand, it's slitted eyes glaring at Relok in disdain and pride "Hello Lantern! I wondered why you'd be on this pathetic planet, turns out you were recuperating! I can't believe my luck!"

Relok grunted "Romat-Ru, the Xanadarian serial killer and yellow lantern..."

Romat-Ru grins "I see that I'm known even to you. Now I can kill you and eradicate this whole planet!"

Rainbow turns to him "Why would you do that?! What's he done to you?!"

"He's a green lantern. I wish to make an example of him and to have killed one of Biot's former prisoners is just a bonus."

Rainbow stares at him "What does his job have to do with anything?! You're both lanterns, you should be friends!"

Relok grunts, his own ring glowing "He's a mass murderer, he doesn't understand the concept of loyalty or empathy."

Romat-Ru holds a clawed hand to his chest "I understand them perfectly! I'm loyal to Sinestro and I can feel the fear of others! But enough talking, you can die along with this colorful eyesore!"

Relok creates a shield, and Rainbow avoids the blast of yellow energy and flies around to Romat-Ru's back and kicks him in the head but to no effect.

He turns and points his ring at Rainbow's face, her magenta eyes staring back at him "I'm not afraid of you."

Romat-Ru grins "How fooli-Argh!"

Relok fires a volley of green blasts at his back, Rainbow evading his body "Nice shot!"

"Get out of here Rainbow!" He yells, green energy forming into a platoon of clones.

Rainbow shakes her head "No way big guy! I never abandon my friends!"

Romat-Ru fires a wave of energy at them, the gladiators shattering like glass "You're not strong enough to defeat me! Give into fear, Lantern Relok!"

Rainbow shoots towards Romat-ru, the alien summoning another wave but she smirks and drops below him, and instead of kicking the back of his head, she bucks his ears, knocking him off balance with a growl "Take that you overgrown chicken!"

His eyes glow yellow as an innumerable number of yellow insects the size of needles appear from his ring "DIE!"

Rainbow grins and flies away, the swarm following her Whoa! These bugs're fast! I wonder...

She flaps her wings and looks straight up, ascending with the swarm and sound of Relok's constructs shattering followed by a grunt Just hold on Relok!!

Out of the corner of her eye, she can see the distant Cloudsdale floating I'm high up enough... now if I remember what I did last time... she inhales and looks down at the yellow insects coming towards her, she swallows her fear and flaps her wings hard, swerving to avoid the clusters of yellow bugs as a cone of air forms on her hooves "Come... on!!!"

The cone glows like the color spectrum, Rainbow's eyes tearing up as she targets Romat-Ru.

Boom. Rainbow thinks to herself, a shockwave of color spreading through the sky, her own mane and tail leaving a similar streak through the sky as her hooves make contact with the now aware Romat-Ru's chest "What are you-"

Whatever he said was lost as his uniform turned entirely black, his ring dimming right before impact with the ground.

Rainbow pants, her hooves screaming in pain and numbness "Awe... some..."

Relok gallops over to the edge of the crater, his ring glowing bright "What did you do, Romat-Ru?!"

Rainbow looks up at Relok "That was... me... never hit anything after my rain... booms before... ow..."

Relok slides down the crater's edge, ring still bright "Is... what did you..."

Rainbow tries to raise her wings but a sharp jolt of pain shoots up her spine "I... I think I pulled my wings..."

Romat-ru groans, an unintelligible string of syllables to Rainbow's ears.

"Uh... did I break his brain or something?"

"Ring, scan his power levels."

A cone of light envelopes Romat-ru's body, and a symbol appears above the ring "He has no power... what did you do?"

"Don't you think you should arrest him first?" Rainbow asks, pulling the dull yellow ring off the prone alien's claws.

Relok nods wordlessly, his ring glowing again and a different voice comes from it "Lantern Tag? Why are you contacting Oa? I was told you were on reserves."

He nods "I was. But a yellow lantern in this sector attacked me. The escaped Xanadarian serial killer, Romat-Ru."

Rainbow shuffles her hooves, holding onto the ring with her teeth and looking at the hoofprints she's left on Romat-Ru's chest Huh, so that's the symbol of the yellow lanterns? Cool.

The voice, a lantern Rainbow realized, continued "You were able to capture him? Alone?"

"No, I was assisted by a local, the one who found me when I crashed here. Rainbow Dash of Equestria."

"...I'll send a contingent of lanterns to return him to Oa for trial. You must come as well and bring the one who helped you."

Relok nods "Understood."

Rainbow looks up from inspecting her wings "What's the verdict, big guy?"

Relok nods, enveloping Romat-Ru in chains of green light "We are going to Oa."

Rainbow grins "Sweet. Don't be a stranger, you're awesome and hey, maybe you could have your boss send a letter about my courage to the Wonderbolts! They'd beg to let me on the team if they knew I helped beat an alien serial killer... okay, having said it out loud, I know that probably won't work."

Relok grins "I meant that you come to Oa with me."

The gears in Rainbow's head turn, processing his words slowly "Huuuuhhh...?"

She gasps "Y-you want me to come with you... to an alien planet? As in, an alien planet?!"

Relok nods "Yes, the Guardians demanded it."

Rainbow grinned wide and shot into the air "Oh my gosh I can't believe I'm going to a different planet! This is awesomer than awesome!!"

Relok grinned in response "I'm sure that the escorts will be along shortly."

Rainbow gasped "I'm gonna go get my camera!"

Rainbow flicks her tail, bored "What's taking them so long?"

Relok sighs "Impatience isn't a great quality Rainbow. Look, they've arrived."

Rainbow looks up and indeed, five green lanterns descend from the sky, each one a different type of alien "Coooooool..."

An orange human looking thing with pointy ears "Arisa, Green Lantern of sector 2815" Informs Relok as Rainbow snaps a picture of each one.

The next, a Xudarian like Romat-Tu "Tomar-Tu, Green lantern of sector 2813"

Next is what looks like a tortoise without a shell "Green Man, Green Lantern of sector 2828"

Rainbow looks at Relok "Don't you know his name?"

"It's more of a designation. Where he's from, there is no individuality."

"Harvid and G'Hu, Green lanterns of sector 2937" He introduces, pointing to a red human with an impressive mustache and a pink and violet man with two long tendrils draped from the back of his head to his ankles.

"Cooool..."

Tomar-Tu walks over to Romat-Ru, still held in green chains "So, we finally caught you again. Maybe without your ring you can pay for your crimes."

Romat-Ru sneers "I will escape and when I do, with lord Sinestro's blessing, I shall eradicate this pathetic planet for humiliating me."

Rainbow growls and bucks the side of his head "You'll never get the chance you fish-chicken freak!" She looks up at Tomar-Tu with a blush "Uhh... no offense officer."

Tomar-Tu cocks his head "I'm supposing you were the one who assisted Relok in his apprehension?"

Rainbow nods, saluting "Yeah! But I gotta say, he wasn't really scary to be honest. I mean, I get he's a serial killer and all, but why did he have a yellow ring?"

Green man walks forward "He is a murderer of thousands of his own people. Children to be precise."

A chill goes down Rainbow's spine, her blood turning to ice water "Ch-children?"

The tall yellow woman, Arisa, places a hand on Rainbow's shoulder "Yes, but you helped in capturing him. that makes you a hero not only to your people, but to the dead as well."

The words pass through Rainbow's ears but she doesn't register them, the chill turning to heat and rage."

"You... you're a monster... no, you're worse than a monster... you're scum."

Romat-Ru smirks "I've been called worse by my own kind. Your words do nothing but fuel me to eradicate everything you hold dear."

"Silence." Relok commands, a muzzle appearing over his mouth.

The mustache sporting man clears his throat "I suggest we get back to Oa. The guardians want to meet the civilian."

Rainbow gives Romat-Ru the stink eye before taking flight

Somewhere on the moon, Princess Luna was building her oft-put off moon laser cannon, a number of tools held in her magic when she notices a mass of green out of the corner of her eye "What the- l-lanturns?!"

Luna shivers, lighting her horn and takes something out of her saddlebags "No... it's too soon..."

Held in her magic is a small purple-blue object.

Rainbow gasps "Oh my gosh! I'm in SPACE! Oh crap! I'm in space! I can't breathe! T-tell Scootaloo... to keep her hooves... off... my... Playmares..."

Arisa grins "Relok's ring is letting you breath Rainbow. And we're almost to Oa."

Rainbow looks around "Really? We've only been traveling for a few minutes."

Relok nods and points to a giant floating fortress bearing the mark of the Green Lanterns atop a planet.

"Whoa... that's awesome..." Rainbow gasps.

Relok nods "That is the central core battery, it is where all the power of will in the universe is concentrated."

Rainbow grins "So... It's like a giant factory?"

Green Man shakes his head "No, it cannot manufacture willpower, it focuses it. It powers all of our rings and power batteries. Without it, we wouldn't have any power."

Rainbow shrugs "Sounds like a factory to me. So when do I get to meet the boss?"

Arisa grins "When we touch down and get audience."

Rainbow rubs her hooves together "This is gonna be awesome..."

"What do you mean I can't go in?! They asked me to come!" Rainbow yells, irritated.

A tall alien with four arms sighs "I wasn't given any instruction to let you or anyone else in. Please calm yourself."

Rainbow snorts and sits on Relok's back "This sucks..."

Relok walks forward "Lantern Salaak, we were instructed to meet with the guardians regarding Rainbow's actions and assistance in apprehending the yellow lantern Romat-Ru."

Salaak nods "I'm aware of his apprehension but not of her involvement. As far as I was informed, you defeated him alone."

"I helped! I was the one who beat him, held him down, and landed the last blow! Relok helped just as much as I did! Can't your ring tell if I'm lying or not?"

Relok shakes his head "I'm afraid that the rings lack that power. Salaak, I swear on my oath that I was told to bring her to Oa and meet with the guardians."

Salaak sighs "I'm not questioning your words, I just have not been told to let you in."

"We did not think to inform you Lantern Salaak."

They all turn and floating in front of a large door is a little blue man with white slicked back hair.

Rainbow raises an eyebrow "You're the one who called us? I never would've thought that a little blue man would control all these lanterns. Whatever, My name is Rainbow Dash. Nice to meet you." she extends a hoof in greeting.

The man stares for a second and turns away "Come, we have much to discuss."

Jerk. Little old blue jerk.

Rainbow shuffles her hooves, eyes locked on the centre guardian "So... do you want me to tell you what happened or are we good?"

The guardian nods "We are here to ask why you helped Lantern Tag, an alien whom you met not even three of your planet's days ago. Why would you throw yourself into the line of fire for a stranger?"

Rainbow shrugs "Relok's my friend, what other reason do I need? He would've done the same for me, but that's because it's his job. I did it because I wanted to help."

"That does not answer our question" a different guardian says.

"Well that's the only answer I have." Rainbow replies.

"How did you drain Romat-Ru's ring?"

"Beats me, I just wanted to help Relok and the best way to do that was to drive him into the ground. I think... and I'm not an egghead, but I think that my magic sucked it out. I mean, I felt like something was coming through my hooves when I hit him. I can't really explain it."

The first Guardian looks at her impassively "You say you siphoned off fear energy through contact? How do you explain that?"

Rainbow shrugs "Heck do I know. All I know is when I hit him his clothes turned dark and his light-bug-things disappeared."

Relok steps forward "She speaks the truth. She drained his power completely. I do not know about her 'Magic' but from what I observed, the inhabitants of Equestria are akin to our own rings. They seem to utilize power gained from harmony with their world. But it is varied between individuals."

A bald guardian turns to the others "Brothers and sisters, I have a hypothesis about her abilities."

The first one turns "What might that hypothesis be?"

"That these 'Equestrians' are living, biological counterparts to the Sinestro's modified Manhunters. I suggest that we test to see if she can utilize a power ring."

The other guardians pause, pondering the suggestion before nodding in unison "Agreed."

Rainbow flies around the large battery, testing the air resistance of the vacuum "Wooooo!!!"

Needless to say, she was having fun.

Arisa watches her, sitting next to Relok "She is very energetic, but why did she face down an alien psychopath without batting an eye? You'd think that she's be scared for her life."

Relok nods "She seems to put the wellbeing of others above her own. She not only assisted me, but also showed me that there is more to life than just duty, there is companionship... and I felt at home on that planet."

A tentacled lantern floats down to the duo "I'm assuming the prismatic blur is the one who has caught the guardians' interests?"

Relok nods "Rainbow!"

She swoops down, landing in front of the three lanterns "What's up, guy?"

The lantern scoffs under his breath "I am Lantern Shorm of sector 40."

Rainbow blinks several times, "You're Shorm? We've met already."

He nods "Yes, we spoke before. I'm here to administer your test. So please try not to damage anything."

Rainbow salutes and Shorm places a ring around her free foreleg "Try to create a construct"

She shrugs and looks at the ring "Uhhh... do I need to charge it or..."

Relok shakes his head "If my hypothesis is correct, you are a living battery."

"Okay... what do I do?" Rainbow asks, inspecting the ring on her leg.

"Simply recite the oath." Relok instructs, pointing to the central battery.

Author's Note

Romat-Ru is the most vile serial killer in Xudar's history, responsible for the deaths of thousands of children. He was sentenced to life in prison, but during the transport to jail, he was recruited by a Yellow Lantern Corps and joined the Sinestro Corps.
source: http://dc.wikia.com/wiki/Romat-Ru_(New_Earth)

A veteran green lantern and second generation lantern, after her father. But her appearance hides her immense skill.
http://greenlantern.wikia.com/wiki/Arisia

A second generation Lantern, after his famous father Tomar-Re. Originating from Xudar, he is good friends with many lanterns.
http://greenlantern.wikia.com/wiki/Tomar-Tu

A veteran lantern, he desired to know about individuality, a thing that was taboo on his home world of Uxor. He is annoyed by his partner's wandering and has partnered up with a lantern from a different sector.
http://greenlantern.wikia.com/wiki/Green_Man

Formerly retired lantern, he had committed his mad brother Harvid to a sciencell but once again took up the mantle of lantern when he escaped.
http://greenlantern.wikia.com/wiki/Harvid

A warden on his home world of Takron-Galtos, the prisoners broke free and used him as a hostage. By the time the other guards had gotten to him, he had subdued all of them and was waiting for them to open the door.
http://greenlantern.wikia.com/wiki/G%27Hu

Veteran lantern of the highest caliber, senior administrator and keeper of the book of OA. Also the clarissi, second in command after the guardians.