Disclaimer: I don't own Transformers

Prompt: If You Want To Live - Run

Warnings: Unnatural body morphing (kinda)

Notes: Written for the 2014 Prowl/Jazz Community Anniversary Challenge wayyy back in... September? But it spawned some more ideas and this is where I'm going to store any more expansions on this AU enjoy!

The anger was blindingly cold in his lines. It caused a dark cramp in his chestplates, squeezing his spark like a Constrictor and it was all because of one of Optimus Prime's advisors, a mech named Jazz.

The council had given him to the Prime like a long over due inheritance, which technically speaking he was, after the annihilation of Praxus. A good will gesture to the newest Prime, proof of their power and support, after all, what mechs could boast without prosecution that they had captured a Crystalline but them?

He was clad in black and white armour, crushed into his metal prison, forced to take only two forms for the rest of the Matrix of Leadership's existence, three if you included the transformation sequence of his mech form. Oh they had been clever, his captors and tormentors of so long ago, binding him with an ancient ritual to the relic all worshipped, yet only the power hungry craved.

Optimus' advisor had known what he was on sight, being a mech that thrived on secret information and all, faceplate draining of energon in horror, as he stumbled back from the introduction. "You're the Crystalline."

Prowl snorted, already in a bad mood as it was, methane puffing from his olfactory sensor, causing the vibrant crystal sapling on Optimus's desk to brighten and levitate higher. "Glad to see somebody realises that I am not just a bundle of metal and wires."

"Prowl, please." Optimus warned, "Be calm. I don't need you shedding your metal skin again in the middle of the base."

"Optimus, when were you going to tell me about this?!" Jazz cried in horror, "Do you even know what he is?! Not to mention how many natural laws this breaks!"

"I'm telling you about him now." The Prime said, honestly confused, "As you've said Jazz, Prowl is a Crystalline that is bound to serve the Matrix until it is destroyed..."

"Or emptied." Prowl chimed in, flicking a doorwing irritably.

"Or emptied," Optimus continued as if the interruption hadn't happened, "As for rules, I have heard of none."

"It's natural law that all creatures sentient and benevolent be left free to roam Cybertron, it's written in the Archivist Text!" The blue opticked mech growled, optics fiery, gesturing in frustration, "Hand written by the First Thirteen Primes!"

Prowl raised an optic ridge in interest swivelling his gaze to the befuddled Optimus, "You command a devout follower of Primus' teachings. Not since Zeta have I seen such negativity to my presence."

"Not towards you personally." The black and white mech was quick to amend at the slightly hostile tone. "I've seen a Crystalline, a free one. He tended his gardens in Polyhex with glee like any nature fairy should."

Prowls optics darkened, narrowing as he shook with an uncontrollable fury, "You imply I do not do my duty to my gardens."

"I know you do not. Bound to the Primes as you are."

Before Optimus could stop him, the Crystalline seemed to stretch, a sickening crunch making the Special Operations mech cringe, drawing a dagger on reflex as the being of pure near indestructible crystal shed its binding prison.

The doorwings broke away first, dropping to the floor, energon and lubricant dribbling from the hinges as something seemed to struggle free from Prowl's spine. The black and white armour faded grey, the battle hardened metal splitting cleanly down the back strut in a thunderous snarl as a bright luminescence glowed beneath the metal flesh.

The Tactician's servos burst in a shower of pink liquid as they became long translucent talons, each digit a terrible scythe peppered with imperfections pumping with methane and crystal dust, the lifeblood of the creature beneath. His legs ripped, pedes popping as a whole foot became three claws, a horrible clasping digit springing from the heel like a poisonous barb. The helm came last, shaking free of its metal confines into the perfect ethereal face adorned by a glowing crown of ruby crystals.

"Those fools you call a council didn't just capture any old Crystalline, any old fairy." Prowl hissed, his voice like nails scraping down a chalkboard and smashing glass all at once. "Back in ages past, you would have once called me The Crystal king."

Jazz shook in his struts, Optimus sighing as he looked down at the pile of metal, wires, tubing and energon littering his office floor now that Prowl had temporarily broken free of his Cybertronian skin.

The Crystal King advanced, chest and body aglow with a three dimensional star at the centre of his chest plates, binding runes blushing purple on his wrists and ankles as he snarled, perfect lips pulling back to reveal needle like denta.

"Jazz!" Optimus boomed, "if you want to live past this moment. Run!"

The Polyhexian didn't look back.

===A Joor Later===

After much snarling and a good beating down at the servos of his Prime, Prowl receded back into the armour, fury still running hot in his fake lines. The crystal on Optimus' desk had turned a blood red, shot through with black, fluxing with its caretakers mood. "He is right you know." Optimus said softly after Prowl paused to stroke the child gem, the only remainder of what had once been the Praxus Crystal Gardens, the home of The Crystal King and his children, the origin point of an underground nation that had once stretched from Kaon to Iacon. "You don't do nearly half the gardening as you used to."

Frowning Prowl picked up the gem, poking the tip of a talon through his finger pad and shearing a section, returning the shard to the bowl filled with a nourishing fluid, the blood of its king, to begin anew.

"Where are you going?" Optimus asked curiously as the being posing and actually being his tactician moved for the door, clawed fingers already working at the now dusky blue crystal in his servos, twinkling dust falling to the floor in shimmers.

"To apologise. I didn't exactly make it clear what Garden I tended. I didn't have any grounds to try and attack him." Prowl grumbled, doorwings flaring as if in challenge, turning with a half completed visor in his servos, "And to keep your Saboteur from getting killed the next time he is on a mission. His optics are too expressive."