Just your average PJO fanfiction story with too much similarities with the original (at least for now, don't know about the future).
Only Percy has a twin sister Penny, not an obedient cute little sister but one with a tomboyish attitude and is a partner in crime for our Percy
Of course Sally couldn't get the twins a single room in Yancy Academy as there are only boys rooms and girls rooms, not twins rooms. But with their lovable attitude the school decided that giving them a room to share will reduce most of the complaints received from the dorms. And it reduced the number of fights occurring by more than half and almost all of the complaints were gone. Of course almost all the furniture in their room was destroyed in a single night. Why? because children being away from parents will lead an increase in fun fights, still better than destroying two rooms. And this resulted in the decision that not buying any furniture for their rooms for the current year would be in the best interests of everyone. Going to class with some swells, bruised lip and black eye was the norm for twins. Its not that much noticeable mind you, cause you know a demigod can sleep it off for these minor injuries, still if you are bothered enough to look there would be some hints but it would be hard finding injuries on them especially when they don't fight in the morning before class and they bath before class. For beating others, each can take down two or three persons at the same time, but when together taking down more than ten is possible for the twins with their impressive teamwork. But of course if the opponents know how to fight or have experienced enough fights, it would be hard, but with their physique they can beat five of the same age.
We can't forget Grover now can we?
Being the nosy brats they are, they almost always go rescue Grover, their physically challenged classmate. He won't cry, he will just take the beating without telling anyone or retaliating, so if you feel the urge to beat up someone, that's your guy.
And of course it all starts at the Metropolitian museum of arts.
Grover was really tired from trying to stop his bodyguards from assaulting Nancy Bobofit, your typical school bully with rich parents. Why? They were already on probation, one more punch and they won't be coming to school anymore. That's right not next year, but next day. Just straight up dismissal.
"No punches Grover" the twins nodded at each other.
But when they stood up, Nancy was already in the fountain a few feet away, nearby, but a little more distance than tripping down into it.
"Did you see that?"
"it was like the water grabbed her." A few who saw this whispered while Nancy said "They pushed me." Mrs. Dodds, their favorite ugly old Pre-Algebraic teacher was calling out for them. The twins followed Mrs. Dodds till they reached the greeco-roman exhibition hall. Weirdly they were the only ones there.
"Well well well, now stealing is bad, isn't it children?" Inquired the old hag.
"We know don't worry we will clean the..." started Percy.
"Wait. What? What do you mean by stealing?" continued Penny
"Do not think that we don't know anything Perseus and Pennelope Jackson" growled the angry teacher.
"Alright, alright. Remember the overflowing in the boys toilet? P stole it while I threw it in, but unfortunately when I tried to flush it away it blocked the U pipe." Percy confessed their crime.
"As for your textbook, P threw it at me when I was trying baseball and I swatted it away. We were thinking of climbing the fence to retrieve it from the ranch on the west side of Yancy, but it landed near the stables and a horse shat on it, so we didn't bother." Penny helpfully added.
"Die you filthy sea scum!" Screamed the teacher while changing into a Batwoman/Vampire/Dracula? Bat wings tore through her dress. The wings were magnificent although the grandma's body with sagging breasts wasn't. Clearly her shirt wasn't designed to let her grow wings. Also her nails grew into ten claws and twelve talons. Yes twelve, two grew towards the back from her heels, like an eagle's. Clearly to pierce and grab something during flight. They looked solid, strong, sharp and deadly. Although the twins fight/flight/fright response was to fight, common sense told them that they didn't have anything that might hold against those claws. They ran interweaving among the gigantic statues and pillars in the enormous hall. Thankfully the height of the museum wasn't much larger than the statues. And with those huge ass wings, the Batwoman couldn't freely fly with all these obstructions. After finishing a round of running in the hall, the siblings arrived near the knocked down shelves of exhibits. They just grabbed whatever they found and threw it at the monster. To their horror, all of it, All of it just passed through her. But fortunately each of them brought them about less than half a second of glitching? So they can't fight, flight was the only option. They then grabbed whatever the small and not so heavy things (relatively) they could and ran for the exit hoping whatever it is in their hands wouldn't fall on their legs with sharp/pointy edges. Fortunately, the greeco-roman exhibit hall was not in the center, but on a side of the museum and there were windows. Unfortunately Penny emptied herself of shortswords, daggers, knives, arrowheads and coins before reaching halfway towards the exit. Percy started throwing soon after that, not interrupting the chain of flying whatever it is. Halfway towards the window there was a sword in its own stand, like it was something special. Three swords actually, arranged in the middle of the hall like the foci and center of an ellipse. Probably used by some kings or generals. Of course Penny took it. About ten to twenty metres from the window Percy too ran out of things to throw. Penny then threw the sword, praying that they would have enough time to get out and with other people around, this Vampire grandma wouldn't kill them. Surprisingly the sword struck on her wings, an inch above, she would have lost her left arm. The abomination was surprised, then it shrieked, like fingernails scratching on a blackboard.
Then there was someone calling "Percy!"
It was Mr. Brunner, their Latin teacher sitting in his wheelchair at the front of the exit, the real exit. Towards the direction of Egyptian section. He threw something at Percy. A pen to be exact. Wtf is Percy supposed to do with a pen? Write an apology? Draw on its face? Wings? Right, the ink must be poison. The monster was already out of its stupor and was rushing towards them. By the look in its eyes, it was angry, very angry. So neck or heart to kill fast, right? Here only neck is an option cause with her unholy but big breasts it doesn't matter how fast you can throw, unless you can throw at the speed of a bullet from gun, the pen clearly wouldn't get to her heart. Percy caught the pen by the cap and flicked it towards their former teacher, praying that it would kill it cause they clearly didn't have much time left.
Then something weird happened. The pen, its body began to grow, but the tip grew multiple times faster than the body. Then a three feet long sword pierced through the neck of the monster, with only hilt and handle visible in the front. Surprisingly the monster didn't fall down after its death, but the sword did with a clang. The monster just disintegrated into millions of golden particles, which flew with the wind. But there clearly was no wind.