Disclaimer: I do not own Percy Jackson or One Punch Man. They are owned by Rick Reordian and One.

Also this is my first attempt of writing a piece of fanfiction, so please don't flame me too badly.

This story will mostly contain events from the book, but may contain events from the movie as well.

Sorry for all of the false updates, I am reading the comments and going back to correct abything you guys point out.

Hope you enjoy....

Story Start:

Percy sighed in disappointment while he killed a cyclops with a single swat of his hand. Was it him or were these things getting weaker? Nah, these monsters must be the runt of the group. "And I thought that these cyclops were supposed to be one of the stronger monsters". Clearly they weren't though. Or maybe they were, he couldn't tell these days. Everything seemed so weak.

"Welp, I guess I should to class." Though Percy knew no one besides Mr. Bruner would care about his absence. In fact, Percy wondered if there could be worse teachers. Almost all the teachers in Yancy Academy were not good teachers. While they didn't physically abuse the students, they did not stop themselves when it came to insulting students.

Not that the insults affected Percy at all. Though he worried for the mental health of his classmates.

'Not that there's anything I can do about it' Percy thought. So he pushed that thought out of his head.

Looking at a clock on the wall he noticed that he only had a couple of seconds to make it to class.

The rest of the day was uneventful for Percy. Absolutely NOTHING happened at the academy. It made the day very long and boring for him.

However, news of a field trip to a local museum brighten his mood immensely. He knew that the chance of not seeing a monster was extremely low. And the thought of fighting a monster that possibly could match his strength excited him to no end. Until then though, he could wait.

It was on the bus to the museum that something interesting happened.

Nancy, being the bully that she was, decided to start messing with Grover. It started small, with her doing things like kicking the back of his set. However it soon escalated to her throwing things at him.

Mr. Bruner finally noticed something when a stray piece of Govers lunch flew and landed on his lap.

With a near murderous glare he turned to Nancy, noticing how she was still throwing things at Grover. "What is the meaning of this?" Mr. Bruner said calmly, despite being a little angry at her for bullying one if his Satyrs.

At the sound of his voicy, Nancy quickly turned around and paled. "Wh - what?" she stammered. "I asked you what you were doing to the other student Ms. Bobofit" Mr. Bruner stated once again.

"I -I no he started it, I swear" Nancy nearly shouted to the teacher in an attempt to not get into trouble again.

"You now have a detention after this trip for both lying to a teacher and bullying another student" Mr. Bruner said loud enough for the entire hearing.

Once they entered the museum, Percy was immediately intrigued by all the ancient stuff.

"This stuff has been around since ancient Greek" Mr. Bruner stated. 'That's a pretty long time, wonder why they need all this stuff though' Percy thought.

Finally they arrived at a giant statue of a man who appeared to be eating children.

"Percy, can you tell me who this is?" Percy honestly had no idea who the baby eating man was. However, suddenly a rush of knowledge came to his mind.

"That guy is Kronos, he's in the process of eating his children because of the fear that one day they will betray him." Of course his answer shocked nearly all the students. I mean why wouldn't it, this was Percy, the guy that was barely passing any of his classes.

"Very good answer Jackson" Mr. Bruer said, a proud glint in his eye.

Things quickly went back to being boring to Percy as nothing eventful happened for a lengthy period of time.

Of course, Nancy wanted some revenge on Grover for 'getting her into trouble'. She totally ignored the fact that it was her fault for bullying Grover and getting into trouble.

"Hey you freak" Nancy shouted at grover as she angrily approached him. "Wait, we can talk about this." Grover hastily said noticing the approaching danger.

Nancy didn't listen and proceed to dump her glass of water into Grovers lap and laugh at him. This of course made Percy a little upset with her. After all, Grover was his best friend, if he didn't stand up for him, then who would?

Percy preceded to get out of his seat and approach Nancy. "What are you doing loose--" Percy didn't give her the chance to finish her sentence as he gave her an extremely light push. This caused Nancy to literally fly off her feet and soar into the nearby fountain.

Percy didn't even get the chance to relish in his small victory as an angry voice shouted behind him."Perseus Jackson, what do you think your doing!" Percy sighed, he knew that this was the beginning of a very long day.

"Ok" Percy said as he followed Ms. Dodds into a random room somewhere in the back of the museum.

Turning away from Ms. Dodds for a second, he admired the artifacts in the room, Percy asked "So what punishment will I get this time"? As soon as he finished saying that, he heard a loud noise from behind him.

Turning around quickly, Percy say that Ms. Dodds had somehow, in the span of a couple of seconds, managed to climb up the excess scaffolding in the room. 'Something isn't right here' Percy thought to himself quietly. 'There is no way an old lady like her should be doing dangerous things like this'.

Deciding to voice his thoughts, Percy yelled out "Get down from there before you break a hip or something".

Ms. Dodds was not amused. 'Who does this brat' think he is. Thought Ms. Dodds, aka: Alecto, one of the three furies of the underworld. Never mind that, the boy could be punished for his language later when he is being punished in the afterlife. "Give me the bolt Jackson" Alecto thindered in her demonic voice.

"The what?" Percy questioned as he couldn't really hear the teacher that well.

"The bolt" Alecto nearly screamed in rage at the imputent half-blood.

Once again, Percy couldn't hear what she said. "First of all, get down from there before you hurt yourself. And secondly, I can't hear what you are saying, you are too far away.

"RAAAAAAAAAAAAHHHHH" Alecto screamed as she finally lost her patients. Quickly turning into her monster form, Alecto jumped off the scaffolding and charged at Percy.

"Die you halfbloo-Urk". Percy had not even given her time to finish her sentence as he backhanded her across the face. Not only did this make the hybrid bat thing turn into dust, but it also made said dust launch with enough force that it cut straight through the wall at the other end of the museum. Strangely, the hole left by the dust had an oddly human like shape to it, almost as if Ms. Dodds decided to use the last of her power to take her revenge on the wall.

"What the hell was that"? Percy absently wondered as he stared at the golden remains of his now late math teacher. 'Was she a monster this entire time?, huh, I never would have guessed'.

No sooner that that thought had crossed his mind, Mr. Bruner came charging into the room.

"Percy" he yelled as he was about to take action and save him from the suspected monster.

"What's wrong Mr. Bruner" Percy asked confused as to why Mr. Bruner of all people had come rushing into the room like that.

"I have come to-" Mr. Bruner never finished his sentence as he noticed the golden remains of a monster as well as a human shaped hole in one of the walls. "What happened here" he asked his student, confused as to what could cause so much damage.

'Crap, I can't let him know that I caused this much damage. The museum will sue me if they ever find out" Percy thought to himself as he hurriedly thought of a lie.

"Ms. Dodds turned into a bat like thing, and then decided to run through the wall". Remarkably, Percy managed to say this while keeping a straight face

'He's lying' Mr. Bruner sweatdropped. "Ok then Mr. Jackson, will you please come accompany me to the school nurse then to check if you are alright"?

Percy, happy that he had not been found out, happily agreed to follow him.