The Terrarian Sun and Moon

The two spirits sat in their damp cell. It was a small stone cell, fit for two ponies. Not terrarian spirits. The cell was 7 by 7 by 5, all made of stone. You could see the moss growing in the corners of the cell and dripping onto the bed. This disgusted the terrarians, but they had to deal with it.

"Why do we have to sit in here, don't they have higher cells?" Mon complained.

"Look Mon, we can't do anything about it besides just break out, and that just seems like a bad idea. Even if we could, we still have to meditate to get enough power to shoot strait out of here." Sol explained.

"Then why don't we do that? We can argue our point across to those two leaders. We are embodiment's of the light and dark, we have our own countries, we know how to talk to them." Mon asked.

"I guess we could, but where would that put us? We break out of our cell, leaving it a mangled mess. We would have to fight our way out, hurting a lot of the guards, and just for that we would be in here rightfully."

"We could just use some potions to get out. I found out how Ethereal Mist is like how he is, he actually uses a potion that is made up of moonglow and something called the ghost plant. We could just phase through the bars."

"Well, it is a good idea bu- shh, Mon!" Sol said, "Somebody is coming, maybe to let us out." Sol pointed over at the oncoming pony guard. 'They always look generic' He thought, 'White coats with gold armor and blue mane. I think they might dye it.'

The two spirits watched as the guard walked by, ignoring their cells, and continuing on. He stopped in front of a different cell and turned around with another prisoner, saying, "Time for your execution. Don't fight back, or it will get worse."

The criminal in question just had a slit smile on his face, and was covered in white paint. He was originally a blue pony, you could see it by the original coat, while his hair and tail were a raggedy green. He had black paint around his eyelids, Laughing all the way. His cutie mark was just a picture of a jester on a playing card.

As the guard walked by, he spit on the two spirits. On of them burning up near Sol, and the other being frozen near Mon. They sighed.

"Well then, I don't feel very against the idea of escaping. Gimme that potion." Sol said, and took the potion, which regenerated as it left the bottle. Mon took a swig to, and they both became ethereal. They were completely invisible, and they splashed some on their armor and it got the same effect. They just looked like a shimmer in the air, and the same guard that had spit at them was without the weird blue pony. The spirits cancelled the effect of the potion temporarily.

"Do not spit on spirits, dude. Not a smart idea." Sol laughed, and added:

"Now we have to teach you a lesson." Then they both hit him upside the head with the blunt edge of their Excalibur's. Mon's was completely covered in a shadowy ice, which froze him completely. Sol's was 1000 degrees so it just melted the ice and gave the guard enough heat to knock him out.

"Dammit... quickly, put back on the potion. I don't want to do this again." Sol said, and quickly covered himself and drank the potion. Mon followed, just in time for the guards to come. They put up a small illusion in the cells until they revealed themselves later, and realized they didn't know where they were.

"Well, let's just look around for them. They can't be to far."

So the two spirits looked around the castle, completely invisible, for the two sisters. They were running around for three hours and decided to enjoy it. They didn't have much time, before they head "Dammit! The Joker got away! Again! And then a "You gotta admit, it was a funny magic trick."

They reached the court room after that, and found the two leaders.

"Where are those two trespassers!" Celestia yelled. She was greeted with Sol and Mon both ending their ethereal potion and appearing in front of them, in the defense stand.

"You called?" They both asked. Everyone in the room was startled, even the princesses. "Excuse what we just did." Sol added. "We apologize for startling you, the first time and this time, but we couldn't help it!"

"Well, no harm done, I guess... but that was still annoying." Celestia deadpanned.

"Hey, when you're as old as we are, you need  a sense of humor."

"We shall now start the trial of these two humans." Luna said, ignoring what the two spirits said. Meanie.

"Excuse me," Mon said, cutting off Luna. "But we aren't human." This caused a gasp from the entire crowd, and the princesses.

"Well, what are you?" Celestia asked.

"And do you not know manners? Respect your leader!" Luna said, demanding respect.

"Not our leader." They both said to Luna, causing her to start losing her patience. Again. "And to answer your question, Princess, we are Sol and Mon, terrarians, and the spirit of the light and the dark. Respectively." Sol Motioned to him and then his brother. The two princesses looked wide eyed at the terrarians. They took in their details. Mon was a complete shadow, nothing was blacker than him. You couldn't see anything behind him, and he had infinite depth. He had bright yellow glowing eyes. Sol, on the other hoof, was a bright yellow, glowing the brightest light. He hadn't hurt the eyes of anyone, careful to not beam it into their eyes. He was almost pure light, like Mon though, he had a physical form. Like a living shadow and a living light. Sol's eyes were exactly like Mon's body, an endless, purest shadow.

"Lies! You cannot be the spirits of the light and dark! You are monsters!" Someone from the crowd screamed, pointing to the princesses.

"Yeah! Celestia and Luna control the sun and moon! Not you two!" Someone else yelled. Celestia and Luna looked at them both, shutting them up.

"Monsters we may be to you, but we still have complete control over the sun and moon." To demonstrate, Mon snapped his fingers, making a dark mist fly from his hands. The mist flew outside, and suddenly it was night.

Sol responded by scolding Mon, and doing the same, making a light shine out and make it day.

"Ahem..." Celestia started. "They have a point. We control those two celestial bodies."

"How long have you had these titles? And just so you know, we don't want to give another demonstration." Mon asked.

"We will not give such information." Both princesses answered, startled.

"hmm..." Sol said, darting his eyes many different ways. "14 billion, hmm?"

"How... how did you know the number?" Celestia asked.

"Mind reading, I can do it when near a person, pony, anything really. Also, we have you beat. We have been alive for 267 billion." Mon clarified.

The princesses looked extremely surprised. "If any notice by us, we don't come from here. If that settles you, of course."

"And we just fell through, not by choice. This explains why we were armed, since we didn't know where we would end up." Mon said.

"Well.. I still cant understand why you were armed coming into Equestria." Celestia said.

"We didn't know where we were going to end up. We COULD have ended up in the deepest pits of the demonic dimension." Sol explained.

"Well, I guess it explains the armed thing. That was the last charge besides the knocked out guard. Why was he knocked out?" Luna asked.

"He spit on us in our cells, so we hit him with the blunt of our swords."

"How did we not find anything on you two, by the way."

"Inventory, kinda like a personal pocket dimension."

"Well then, I will also have to look into that and talk to the guard..." Luna said, glaring at the guard. He flinched. "Where will you go, though?"

"We will go to the closest place here. I don't like this town, so the closest will do." Sol said.

"Then Ponyville it is." Celestia said, smiling. "Good choice, but I hope you can manage."

"Well,  that is a good way to start things off. Bye!" Mon said, and moved into a single ball of shadow and darkness in the air, and sped off towards the closest sign of civilization, soon followed by Sol.

"Goodbye, spirits. We grant you a good day and night." And Sol moved into a rainbow ball of light and sped off after Mon.

"Well then. Case dismissed!" Luna shouted.

All the ponies scrambled out of the court room, leaving the princesses.

"You think they are a threat to Equestria?" Luna asked.

"Very much so, but we will keep an eye on them. They are immensely strong, and would take out all of this nation and others, even the dragons. They would take the whole planet Equestria, and we wouldn't be able to do anything. Raise an army, train them, we need to take these two down." Celestia responded.

A guard overheard her from the door. "RIGHT AWAY PRINCESS!" And he sped off towards the barracks.

"Keep an eye on them from the moon, Luna. Don't let them out of your sight." Luna nodded, and Celestia looked on them from the sun. "I will figure out your true meaning for being here, I will not allow this planet to fall under your rule." Celestia thought. She then heard a cackle from the distance.

"GUARDS! JOKER ESCAPED!" Celestia yelled, then went back to meditating.