"What could cause this much damage and suffering in so little time!?" twilight asks the princess's as they fly over whats left of soft rock mine.
the whole town has been reduced to rubble and ash, the only sign there was ever a town there is a singular burnt sign. Chard corpses litter the entire site, all silently screaming from the agony they faced before death. The mine itselfhas collapsed but due to the shear size of the tunnel that remains they could still go down there if they wished to do so.
using their magic the spill light down the now abandoned mineshaft and start making their way down into the depths of the earth. With the occasional piece of rubble and rock rolling down ahead of them, gaining momentum as they get deeper and deeper into the mines depths.
The ground suddenly starts shuddering and the twang of wire reverberates from the enterance of the mine as a loud mechanical laughter chases after them. With the torso of the mechanical beast blocking the only exit the trio of princesses are forced to turn and face it.
upon seeing the flowing mane of luna the mechanical beast releases an almost hiss like noise and steps back. "You should be dead! Why arnt you dead!? I ended all the lives of the alicorns! How do you still live!?" The mechine yells in a confused yet enfuriated version of his own voice.
upon hearing this they scowl and luna goes to say something but is cut of when the beast simply turns around and walks away with enough smoke comming out of its chimney to block the sky for hours.in clear anger it starts destroying a large forest, stamping, snapping and burning every single tree and bush there.
"Princess luna, did you sea what was on the side of him?" Twilight asks in a confused manner.
"We did see. It worries us greatly" luna replys staring at the spot where the gargantuan machine once stood.
"I need to get a closer look." Twilight says as she trots forward. "if I can get answers from him I might be able to solve this mess"
She exits the cave and spreads her wings ready to take flight but is shocked to find both celestia and luna beside her.
"W, what are you doing? I dont want to get anypony hurt when im attempting to get answers from him." Twilight states in a almost whine.
"Thou arnt the only one after answers twilight. He knows more than he is showing" luna says
the trio take flight towards the mechanical beast and closein beside it. On the side of its torso the word promeathius is faded and a symbol very familiar to both luna and celestia is next to it. Its a picture of space and all its stars, the symbol of his creator. The alicorn prince whom made him.
"It cant be! You where defeated before either of us even existed! PROMETHEAS! DO NOT IGNORE ME!" celestia shouts in her canterlot voice.
the smoke stops pouring out for just a second before prometheas turns and all three of them get the fealing hes glaring at them.
"Dont you, DARE! You dare use your canterlot voice on me, young one! If you shout at me because of whatever you heard I did to youre ancestors your anger is miss placed!" promeathius roars back making celestias canterlot voice sound tiny. After this promeathius turns towards the nearest mountain and starts making his way towards it.
All three princess's just hover there stund from both what he had said to celestia and the volume of which he said it.
"Wait! Please!" Twilight begs flying towards him as fast as she can.
"If my creator had known that all the stories and information passed on by elder alicorns would turn into one sided lies he would of have me destroy myself and take all equestria with me!" Promethius shouts to himself clearly unaware of twilight begging for him to wait and answer her questions.
the ground below him suddenly gets very steep and is no longer dirn and grass. He is now scaling the side of the mountain with twilight following.
"Please! I just want to know what happened..." twilight says sadly, seaming like shes about to give up.
hearing this caused promethius to stop dead in his tracks. This made him think and also grow in anger aswell as a almost bottomless saddness. Not only did the alicorns that betrayed him make him the 'bad guy' but their children try and wipe all memory of him and all chances of the true story comming out! His master and creater died because of an accident caused in his rage that was brought upon by his leaders. He allowed himself to be defeated because ne had killed his creator and his only true friend.
"I will tell you what happened that dreaded day. That day my existence whent to tartarus and the traitors where known as heroes and heroins.the day my only..." he cut himself of there and his whole body creaked causing twilight to wince.
Twilight flew up to him and softly said "its okay. I will try and help if I can."
"It happened just after I had finnished a small training sesion, I returned to the encampment that me and my creator where based at for defencive reasons when I heard him and at least 15 other alicorns arguing. I could see their shadows on the side of the tent. One was tied to a chair while the others where torturing him. It was only when they had stabed him I realised who it was in the chair. I had crushed half the tent in an instant to see that he was still alive but unconsious. The knife was torn away with the tent and blood was trickling out the wound on his remaining wing. They had torn the other off. A large group of them attacked me from behind, one had a mane like the stars with a slight green tint to it. She was the mother of master and the one leading this assult against me. I tried to stay calm and olny wound them so I could explain why I acted the way I could but they where trying to kill me and master. They soon realised that their attacks weren't doing much against me and so whent after master. The first attack sent himm to the edge of the everfree forest. I, I snapped at that point. I killed them, I didnt care that they would soon plead with me for their lives and lives of their foals.i didnt care because they hurt the closest pony ive ever had to family and wanted to kill him. If they wouldnt harm him once I was dead I would have let them kill me but they veiwed both me and master as a target. After they where almost all dead the attacker's leader was infront of me begging for me to let her live. As my leg came down towards her master pushed her out the way and, I, I, killed him... that was when any trace of anything but depresion filled my. Blocked my senses and time seemed to slow to a stop.then laughter. The sound of evil, cruel laughter came from behind me. A whole army of royal gaurd had assembled behind me and masters own mother was laughing. Laughing at me, my suffering, and how I had just killed the only being that ever meant something to me. I killed her. Sent her up in flames then crushed her corpes remains to dust and let the others stare at what had happened. The last thing I saw before waking up was a very deep whole then darkness. Now you know what had happened the day my life fell apart around me. And that is why nopony shall ever think of me as anything but a monster or a mythe. That is why I hate youre 2 mentors. That is why I hate your whole race! Because your race caused me to loose my only friend and family!" Promethius yelled at twilight, startling all three princesses.
he continues his climb upwards as the sun is blotted out by the enormous amount of smoke erupting from the tip of the chimney. Recodnising this to be a very bad sign of his mood twilight gets as far away from him as he can before he desides to kill her too.
"We heard the whole thing from here, twilight. I know understand why we where toldhe was a monster built by a traitor. Because it was a story used to cover the truth behind what had happened. He seems to believe all alicorns and ponies think the same way. I will go talk to him." Celestia says as twilight returns.
"Its a little too late for me to go back.say it was just a mistake? Think theyd forgive me like that. If I thought id be let back in I thought wrong!" Celestia hears him saying to himself as he climbs.
"But youre just like any other being. You make mistakes. I understand what its like being the one to cause somepony who you love as family to die. I had to bannish my own sister to the moon. I had cried for years after..." celestia says. Sorrow lacing her voice.
"But she had returned! You dont know what it feals like to kill somepony youve loved like a farther all youre life! When you bannished youre sister you know she would return! I will never get to see my creator ever again!" Promethius yelled. This stung celestia and hurt her more than she thought could be done with words.
celestia landed on the side of the mountain and cried. This was something he was not expectng at all. He was expecting her to attack him or to attempt to once again seal him away.now fealing increadibly guilty for reducing her to tears after she attempted helpng by unknowingly making a very terrible comparison he stopped and lifted her up using one of his eignt legs.
Being shocked by this action celestia is even more shocked to be put in a balcony type area on the 'head' of promethius. He makes his way back down the mountain and ignores the other two alicorns who start following him towards canterlot. Celestia stands up and finds a singular lever with no indication of what it could do.
Celestias magical grip pulls down on the lever and what seams to be a sphere of fire is lauched from the front of the head and ignites a tree. Within seconds the trees reduced to ash.
"Stop!" Luna shouts and promethius stops dead as commanded.
"What is it you wish for now?" promethius says clearly hapoy to once again have orders.
"What did you just do" She asks
"That weapon can only be used by the passenger. Celestia done it." He replys calmy
At this the trio enter the balcony and stay there fro the entire journey to canterlot. Where panick will surely follow when promethius aproaches with the princess's behind the bars of the balcony.

Author's Notes:

In a couple chapters time theres going to be a suprise meeting of promethius and his most hated race. Please state in the comments what race that should he hate most. The pony race is non included.