Crystal Empire 1500 Years Ago...
"Keep digging!" ordered Sombra as his crystal guard worked faster. "We must save the Princesses and our visitor!"
How could have he been so blind? Why did he let himself be fooled by Tirek's villainy? The fiend had a heart as black as the night he professed to be preparing to bring about. Already the skies were darkening over the Crystal Kingdom. "I will not let him take this land," hissed Sombra. "No. No more. This world has seen enough despair from the chaos Discord brought to our people. Work harder!"
Soon, the last of the rocks were cleared as lights were shone into the cave, and Sombra called out. "Princesses! Wheeljack! Do you still live? Answer us!"
Silence. But then, a faint voice called out from the depths. "Deep within! Wheeljack requires aid!"
Sombra's heart leaped into his chest as several medical ponies levitated the giant out of the mine, and laid him out. "Is he...?" asked the prince.
One of the medics laid his ear against the chest of Wheeljack and bit his lip. "I... cannot tell. I hear faint sounds, similar to breathing. He is warm, but the warmth is fading quickly. He could be dying, and there's nothing we can do to stop it."
"I see..." Sombra turned to Luna and Celestia, the sisters looking tired from their ordeal. "What happened?"
"Tirek. He tricked you, your highness. He used your kingdom to retrieve Dark Energon, and forged it into a weapon. He calls it the Rainbow of Darkness."
"An ominous name indeed," said Sombra. "And what of Tirek? Where did he go?"
"We have a guess," said Luna. "He has erected a castle, known as Nightmare Castle, in a set of old ruins to the north. We will face him, alone. We will return to Canterlot, and retrieve the weapon that will defeat him once and for all."
"My sister is correct. Only the Elements of Harmony can stop him now. Before it is too late," said Celestia. "Though, how effective they might be, we are uncertain."
Sombra closed his eyes and sighed. "Go with our blessing, my Princesses. And know this: I never wished to harm our little ponies, or our friend Wheeljack. If only there was something we could do for him..."
"My Prince, I am getting something," said the medic, drawing their attention. "It's faint, but I believe he still lives. Did he not claim to drink the liquid distilled from Energon? For survival?"
"Yes... he did..." murmured Celestia. She looked into the mine and without warning, charged back inside.
Lighting her way, she lit the paths which were covered in rubble. Left, right, left again. She tunnelled deep into the mine's deepest area and started to dig. Oh, how her hooves hurt but she knew there was some. And soon, she found it: a gleaming chunk of violet crystal. Tearing it free, she charged back into the daylight which was weaning.
"Sister, what madness has overtook you?" demanded Luna as Celestia produced the Dark Energon. "What do you intend on doing with that accursed substance?"
"Wheeljack said it could raise the dead," said Celestia. "He is dying; I will not see it through. Stand aside, Luna."
"'Tis madness," snapped Luna. "This borderlines on the dark necromancy of Tirek! Will you risk him coming back mad?"
"It is the only way," said Celestia as she shoved past Luna.
"Celestia, please, reconsider," exclaimed Sombra as the Sun Princess held the chunk aloft, its jagged spire aimed downwards. "If this could wake the dead, it could spell disaster! What if he dies? What if he goes mad? His blood will be on your hooves!"
"I..." Celestia's grip on the crystal wavered slightly. "I don't know how to save him without doing this. This is the only way..."
"Reconsider. If you go down this path, you are no better than the one who caused him to be like this. Remember the Elements and all that it stands for. Kindness! Remember kindness! Think of Unicron and Primus, think of Orion and Megatron; would Wheeljack want you to walk that path?!"
And finally, Celestia lowered the Dark Energon, the crystal clattering to the ground. She lowered her head, and wept. "No... no... I don't want that... I just want my friend back..."
"Didn't know you cared so much, Princess Sunny-Butt," came a weak voice. Celestia's head snapped up as she gaped at Wheeljack who groaned and propped himself up on his elbows. "That... was one heck of a stasis lock. Miss me?"
Wordlessly, Celestia embraced Wheeljack, giving him a smile.
And then she reared back and struck him full force in a massive headbutt.
"I deserved that," said Wheeljack, dazed as he fell backwards.
=====
Present Day
The ground-bridge opened up, discharging robots that Spike had never seen before. One of them was a truly massive robot, with thick limbs and a barrel-like body all in green. He immediately thudded chests with Wheeljack. "Jackie!" He crowed happily. "Good to see you!"
"Been too long, Bulk," replied Jackie with a laugh. "Come to wreck like Wreckers, huh? Sir!"
"At ease, soldier," stated Ultra Magnus, the huge blue-and-red robot giving the Wrecker a smile. "I see we're working with the locals again."
"You're pretty big," said Spike and Ultra Magnus looked down. "You're going to help us save Twilight, right?"
"You have our word," said Ultra Magnus as more robots came out of the breach. One was a surly red robot carrying an advanced looking medical kit and was arguing with a blue-and-white robot. "Will you two please stop arguing?"
"I'm just saying there's no reason for me to be here on the front lines," argued Knock Out testily. "Smokescreen is just being paranoid."
"And I'm saying we need a field medic, and Ratchet's delegated to you. Our medic." replied Smokescreen.
"So we all know the plan then," said Bumblebee. "Ultra Magnus, are you all right with leading the insertion team?"
"I have got a jet pack hooked up already," replied the unit commander, perfectly willing to take orders from Bumblebee. "I will be carrying the ponies without flight capabilities up to the top of Nightmare Castle."
"Works for us. Anything to save Twilight," said Applejack. "Lyra, you coming?"
"Naw, my place is with the 'Bots," replied Lyra. "This is more your girls' thing. I mean, the six of you are the best of friends; I'll just get in the way."
"Darling, there's always room for one more," said Rarity.
"And it'll be a bigger party when we beat 'em all up," added Pinkie.
"Once we get up there, we'll take out that buckethead and save Twilight, and we'll be done before we know it," exclaimed Rainbow Dash.
Fluttershy just nodded, and then added as an afterthought, "Um, is Spike coming with us?"
"I have a very important job for Spike," said Lyra. "You five go ahead. Spike and I will catch up."
"T-minus 5 minutes and counting. Get into position, everybody, we're going to go in hot." said Bumblebee.
High above in Nightmare Castle, Twilight strained against her collar but she found herself unable to perform the magic needed to escape. Tirek, however, was watching the organization of the rescue with an amused look on his face.
"They think they're clever, striking in two places at once. Little do they know, my troops are already circling around. And soon your friends will join my chariot team."
"We'll never bring about Eternal Night!" yelled Twilight. "Everypony will come, you hear me?"
"Oh poor little pony, I don't care about that. All I care about is getting my revenge on those who wronged me. I had big plans for this world, and you wretched creatures are a plague. Did you ever stop to consider how long I've been trapped in that Dark Energon?"
"1500 years," replied Twilight. "And not once did you learn the lessons of friendship."
"No one knows friendship. No one." Tirek got up and clenched his fist, dark energy boiling from it. "We'll see how friendship-laden your friends are when they're ground into dust. Arise, Stratadons, and serve your master!"
Twilight could see the crystal ball from where she was chained, and the sight of monsters ripping out of the ground made her cry out, "Run, everypony, run!"
"There's nowhere to hide," replied Tirek. "Nowhere to hide at all..."
=====
Crystal Empire 1500 Years Ago...
Wheeljack cut through an enemy, sending it sprawling to the ground as he marched onto the Nightmare Castle. Looking at the front gates, he smirked as he retrieved a grenade and tossed it into the moorings of the building. Detonating it, he blew a hole into the castle as he stormed inside, only to be met by legions of lizards with spears. "Out of my way!"
Kicking and punching through them, he took care not to kill anything, for Celestia made him promise not to. And soon, he climbed to the top of the tower were he kicked the door in. "Knock knock."
"Wheeljack. I've been expecting you," said Tirek, standing up from his throne. "Tell me, why do you fight for this world?"
"Dunno," replied Wheeljack, drawing his swords. "The same reason I always do. I don't like tyrants."
"Fair enough. Now why don't you put down your sword, and I put down my Rainbow of Darkness... and we settle this. Metal-man to centaur." And he set his bag aside as he cracked his knuckles, stamping his hooves against the floor.
Wheeljack smirked and replaced his weapons, shifting into a combat stance. "Sure thing. I'm up for a little rousing game of punch-out."
A long moment passed. As if a tumbleweed passed by, the tension in the air rose. And then, the pair moved, burying their fists in each others faces with resounding impacts. Wheeljack was surprised; this guy could hit hard and he was on par with the blows of several 'Cons he had fought during the war. But he was surprisingly not-squishy either. All hard muscle, almost stone.
"You're not bad," said Wheeljack, skidding backwards.
"I was not the top fighter of my clan for nothing," sneered Tirek, wiping his lip.
"Oh yeah? What happened to them?"
"You'll soon be joining them." The centaur charged him but instead of punching out, he kicked with his front hooves, slamming Wheeljack through a wall. "You're fighting a being with six limbs, metal-man. Pay more attention."
"Oh, I did," said Wheeljack and he held up a detonator. Tirek looked downwards and there sat three grenades.
The explosion crumbled the top three floors of the building as the pair fought all the way down, punching and kicking, smashing masonry against each other until they hit the bottom.
Landing hard, the opponents wrestled with one another as Wheeljack slammed him through a statue, Tirek kicking out with his front hooves as he threw the Autobot into another statue. "Enough!" From the top floor, the bag holding the Rainbow of Darkness fell and he caught it in his hand. "It is time you died, metal-man."
"The term is Autobot." And Wheeljack charged just as Tirek unleashed the full force of the Rainbow of Darkness into his face.
=====
Present Day
The explosions rocked the Castle as Spike stumbled, but Lyra held him up with a burst of magic. "Careful, one step and it's a long way down."
"Oh, don't worry, I'm good at making stairs seem easy," replied Spike with a swallow as they descended further deeper into the castle.
Exiting into the room beneath the castle, Lyra smirked. "All right, set the charges. Press the red button when you've got them placed."
"How many times have you done this before?" asked Spike as he fished out a charge and set it up across the room.
"Too many times," replied Lyra. "We're going to collapse the Throne of Tirek under him to sever some of his power to the earth. That should slow him down if he survives getting hit by the Rainbow of Light."
"This brings a whole new meaning to the word 'combat,'" remarked Spike. "Done. Lets get out of here."
"Right. Lyra to base, we need a ground-bridge. Stat." The portal opened up and the pair leaped through, the bridge closing up as they landed in the receiving area of UNIT. "How are things looking there on the field?"
"Insertion was tricky but doable," replied one of the techs, as Celestia had deemed to go to the battlefield, and Luna was there at UNIT, presiding over the workings. "The Mane Six, er Five are going up to the top. Arcee and Smokescreen are there. The rest of the Autobots, Crystal Guards and Royal Guards are fighting on the front lines against the Terrorcons."
"Princess Cadance?" asked Spike. "What about her?"
"What the Princess has been screaming over the battlefield is not fit for public consumption. She gets mouthy during battle," replied Luna with a smirk.
"Typical Cadance," stated Lyra. "Let's hope the girls are having one better."
Back at the battlefield, the five-plus-two Autobots peered around. "No guards; I don't like it," said Smokescreen.
"It's an open invite, then," said Arcee, holding her gun steady. "Smokescreen, circle around back. The rest of us, we're going in the front door."
Smokescreen nodded, twisted a device on his wrist and sunk into the ground. Pinkie Pie whistled. "Now that was cooooooool."
"On three then?" said Applejack and everyone nodded. Arcee counted down and Applejack bucked the door as hard as she could, breaking it open.
"Girls it's a trap!" yelled Twilight.
"Well DUH," dead-panned Pinkie seconds before magic collars wrapped around the Element Bearers' necks and magic bindings grabbed Arcee and pulled taut. "I mean, if we didn't know it wasn't a trap we would have blundered in way more unprepared than we are now!"
"Pinkie, now's not the time t'be runnin' your mouth, sugarcube," sighed Applejack.
Clapping, and Tirek stood up. "Bravo, ponies, bravo. I see the long years of my imprisonment has yet to dull the humor of your world. Brilliant."
"Let them go, it's me you want. You need four ponies to drive your chariot, which means you have 3 more right?" demanded Twilight.
"Oh, it was never about the chariot. I told you this, my dear Sparkle," sneered Tirek. "This is simply about revenge. Now, where are Wheeljack and Celestia and Luna?"
"That's what this is about? You want the Princesses and Wheeljack?" demanded Rainbow Dash.
"Of course I do! They ruined everything and forced me to endure it. The sounds, the breathing, the mad, mad drums in the night, all of it! Even the sweet release from his voice could not stop the rage boiling in my mind!" yelled Tirek.
"Of course, it all makes sense now," said Arcee. "They said they trapped you in Dark Energon. And Dark Energon is..."
"Our Lord and Master, UNICRON," snarled Tirek, cursing and revering the name. "Even now, through space and time, I can hear his wails and rages. It never ends, it never sleeps. I will end it all in his name, and his name alone! And then I will be sated, whole..."
"Whoa, somepony's gone completely off the wall," whispered Rainbow Dash to Rarity.
"Quite. He is quite mad." replied Rarity.
"Even now, this world connected through space and time to our master's home planet isn't enough to distance me from him," half-sobbed Tirek. "That is why I will defeat you all. Celestia! Luna! Wheeljack! Come and face me, or face the extinguishing spark of your little ponies!"
"You rang?" Dropping out from the ceiling or rather through it via Smokescreen's help, Wheeljack grabbed Tirek and slammed him through the wall and out into the courtyard in a freefall. In the same motion, Celestia appeared in a flash of light and her horn glowed, breaking the bonds that held her ponies.
"Quickly now, while he's distracted, use the Elements of Harmony!" ordered Celestia.
"Right!" The six assembled as Wheeljack held the tyrant in freefall, and Tirek yelled out as the rainbow came plummeting at him.
"NO! Rainbow of Darkness to me!"
A torrent of black energy erupted from the ground, and engulfed Tirek, throwing Wheeljack into the wall. It wrapped around him, the colors of the rainbow in washed out shades of black and silver swirling around the crazed centaur.
"I will destroy your world, in Lord Unicron's name," snarled Tirek, firing a beam that obliterated several ranks of his own men and throwing guards and Vehicons aside. "Feel this power; the Rainbow of Light will not avail you this day!"
And steadily, the Rainbow of Light began to get forced backwards as the six strained against it as everyone watched.
=====
Crystal Empire, 1500 Years Ago...
Wheeljack strained against the darkness and was thrown into the wall, the wall splintering inwards. Tirek laughed. "Such power, from such a strange force. I will break you, Autobot."
"Enough!" In a flash of light, Celestia and Luna appeared. "This ends today, Tirek!"
"You cannot defeat me," boasted Tirek. "Not while I have the Rainbow of Darkness!"
"A foalish assumption," replied Luna as she brought three gemstones to bear, Celestia bringing three more out of her bags. "For we have a power unmatched."
And the sisters glowed as the elements spun, whirling into a rainbow of light which coursed at Tirek. He fired back, but the Rainbow of Darkness did not hold against the Rainbow of Light, which splintered it under the force, and it exploded. "NOOOOO!" He howled angrily as the Rainbow of Darkness formed crystal around him and soon, Tirek stood there encased in the very material he sought to wield.
"Heck of a light show," said Wheeljack, sitting up. "What was that?"
"The Elements of Harmony," said Celestia, helping him stand. "He will sleep forever, imprisoned in Dark Energon."
"We will seal this ruin, and keep any and all who trespass away from it," added Luna. "For the good of ponykind."
"You shoulda let me kill him," Wheeljack said.
"That is a line we cannot cross," said Celestia. "Come, Sombra will want to know of these developments."
And with that, the trio vanished.
=====
Present Day
Time seemed to slow, as the Elements of Harmony fought with the empowered Rainbow of Darkness. And in that stillness, a voice called out to Wheeljack. "So, a choice must be made, for better or for worse. The rainbow you kept all this time, now works?"
He turned and the Moochick stood there. "The prophecy of a little needed rainbow is needed, yes, but why hesitate when in times of duress?"
"Just thinking... to myself that this could have ended years ago." Getting up Wheeljack grinned at the Moochick. "But regrets aren't something I do."
"Hey, Tirek!" Tirek looked down at Wheeljack who held up the tiny locket. "See this?"
"It can't be..." said Tirek, his voice wavering in fear.
"Maybe a little rainbow is all we need right now." And rearing back, he threw it at the tyrant.
Tirek retaliated, firing the Rainbow at it and the locket was engulfed. But for a moment, nothing seemed to happen until color began to creep into it. The beam from the Elements of Harmony suddenly tripled in intensity, until the whole world turned into a shining rainbow of light. Tirek screamed, and then, everything stopped.
"What happened?" asked Twilight as everyone floated down in the vast white void. "Did we get him?"
"I think we did?" asked Rainbow Dash curiously.
"You did, and you succeeded, good for you! And everything's come full circle too!" exclaimed the Moochick happily and the ponies jumped, including Celestia who gaped at him. "No need, no need to thank, just doing my job. The Moochick is here, and will be at all."
"I don't understand," said Twilight as Celestia moved closer to the group. "What does he mean by that?"
"It means that this is a circle: something meant to happen in the past and the future," said Celestia with a sad smile. "My choices in the past, and Wheeljack's decisions in the future changed everything."
"I hung onto the Rainbow of Light, a little piece of it. I was going to use it for the engines, but y'know," said Wheeljack.
"And that changed the future?" inquired Bulkhead.
"More like fulfilled to a point that is. Always the future splitting off there is. Like a river with the twists and turns, never quite knowing what memory holds," explained the Moochick.
"Now it is time for you all to go, and celebrate your victories. But never forget the things you've seen in history." And the Moochick snapped his fingers as the world resolved around them into a beautiful garden with giant trees.
"Oh, how beautiful," said Fluttershy as everyone, robot and pony came to meet them. "Hello, Mr. Butterfly. Oh yes, good to hear you're taking advice now."
To Be Continued