Easiest way to not make your character a Mary Sue??? Don't make them like Piper. 

LOLOLOL, okay I'll be serious now (but fr tho, don't make them like Piper). 

I'll list the traits every Mary Sue has and how to avoid them.

NAMES:

Mary Sues have such weird ass names, guys wtf. And they're always unnecessarily long? 

I already discussed this in the "Creating Your OC" chapters, but I'll summarize the basic points in case you forget. 

Just do this:

First Name + (optional) Middle Name + Last Name

Don't give your characters names that are anywhere similar to this shit: 

- Marina Blue Seahorse Dolphin Orca Whale Seaworld Oceana Jackson

- Emily Slytherin Gryffindor Snape Riddle Dumbledore 

PHYSICAL APPEARANCE:

The Mary Sue is soooooooooooo beautiful, so so beautiful... that it's a CURSE (sometimes)

They either HATE their beauty or they think they're ugly despite being described as having "✨clear porcelain skin with baby blue eyes and silky blonde hair cascading down her back✨" damn, doesn't that just sound hideous? Sooooo ugly.

They'll be described as absolutely flawless (and white, they're usually white). And if the author uses faceclaims, then it's either an overused one or a supermodel. They're thin with big boobs and a good ass, etc. And another thing, other characters are constantly commenting on their beauty yet the Mary Sue goes around thinking "noooooo stop it, I'm soooo ugly" 

If you want to crank it up even more, the Mary Sue might even have unnatural eye and/or hair color (like Piper fucking McLean and her "KalEiDoSCopE" eyes smh) that nobody else has, ONLY HER. Mary Sues don't have brown eyes, no no no, that's too common, it's gotta be rare and out of this world! Or blue. 

She's also never shown to give any effort on maintaining her perfect looks. No ten step skincare routine is mentioned, no workouts to keep them in shape, no healthy eating, etc. If you're OC is a demigod, then at least they've got the workouts and healthy eating covered (since if they slack off on that, they could literally fucking die. Survival of the fittest, remember), but Harry Potter OCs don't have that chance. The characters in Harry Potter literally eat so many fatty and unhealthy foods and yeah they walk around Hogwarts, but that is NOT enough exercise for the Mary Sue to "stay fit and healthy". 

Stop, stop, stop! 

Don't do any of this, for fucks sake! 

Look, I don't really care if you want to make your OC gorgeous. Just please stop with the "noooo, you're lying, I'm ugly!" every time someone compliments their looks, that's so annoying. And stop making them hate their prettiness too! Who the fuck looks in the mirror, sees all their hot af features and says "Omg, I hate being so beautiful!". And if you're using a faceclaim, STOP USING OVERUSED ONES OR SUPERMODELS!!!  😤 😤 😤

When it comes to the eyes and hair, make it normal for fucks sake. There are some instances where unnatural eye colors are fine, like if you're making a Dionysus!OC, his kids usually have purple eyes. Remember, if it's a demigod, check the wiki to see if demigod appearances vary on their godly parents, because some of them have a hand in how their kid looks. If your OC is just the average witch/wizard, then their features are probably going to be normal unless their a half-breed or a Metamorphmagus. 

If you reeeaaallly reeaaallly wanna give your OC purple or pink or fire-truck red hair, then fine. But have it be done through hair dye. Don't make their hair like that naturally, ugh.

AS FOR THEM MAINTAINING THEIR APPEARANCES! You gotta mention it every once and while. It doesn't need to be a super detailed paragraph about, like, their skincare routine but maybe just write something like "and as usual, before she went to bed she did her usual skincare routine". AND THERE, DONE! 

As for keeping them in shape, if you want your OC to be fit, slim, thin, whatever, then you should mention how they do that too. Again, if your OC is a demigod, you're going have to do this regardless because it's literally apart of camp life and they're always being attacked too. I'm sorry, Witch!OCs but Quidditch is not the workout you think it is... Quidditch is not enough to give your OC a thin, fit body. You're literally just sitting on a broom. It might help with core strength since you're flying, but you're basically skipping leg day. And arm day, and ass day, and yeah, you get the drill. 

Unfortunately, Hogwarts doesn't provide PE (smh), so unless you wanna write about your OC running around the castle for exercise, you should probably stick to them just picking healthier options during mealtimes. 

BACKGROUND:

There's only two choices and no in-betweens. The Mary Sue is either super filthy rich (and they hate it, what a surprise), or they're constantly abused by their parents or something. 

I don't have a problem with any of those, but they're always written terribly, especially the ones where she's abused. It's basically written like this:

I put my silky blonde hair in a messy bun and walked down the stairs. There, I saw my father in the living room. He beats me regularly. 

"Stupid bitch!" He spat once he saw me. He punched me in the face. I went falling down, the skin around my baby blue oRbS turning purple from the bruise. 

I cried. My life is so horrible! I'm always getting beat!

"I should've never given birth to you!" My horrible stepmother shrieked before kicking me in the ribs. "I hate you!" She then grabbed me by the hair and dragged me to the basement. 

I was thrown down the stairs. I cried even more once I hit the ground.

💀 I lost brain cells writing that, btw.

If you don't do research on how to write abuse, then don't bother fucking writing it just so you can give your OC a "tragic backstory". You're glorifying abuse and I hate you for doing that. 

Why do people always go for abuse anyways, what the fuck? There are other ways to give your OC a tragic backstory, it doesn't always have to be abuse. Maybe they suffered the death of a loved one, maybe they and their family became homeless, THERE'S LITERALLY OTHER WAYS! 

Look, if you want to do a tragic backstory kind of thing, then you're going to need to do research regardless. Their backstory's tragic, nobody's going to come out of that unscathed. They'll probably have a lot of mental health issues, and you're going to have to do research on that to write it correctly. 

If you DON'T want to go through the effort of doing any research, then toss the idea of giving your OC a tragic backstory out the window. Give them a normal decent life because at least that doesn't come with many psychological ramifications. 

Actually, if you don't want to do any research at all, then just forget writing a fanfic in general. You're going to need to do some sort of research regardless for literally anything that goes on. If you want to be lazy and not do research, then I'm sorry, but don't bother writing a fanfic. 

SKILLS:

They're stronger then Percy or stronger then Dumbledore and get this... they became that way naturally! So cool, wow, I wish I was her. 

From day one (or chapter one in this case), they're just... hella powerful and strong? They can defeat monsters with ease or do spells and shit??? 

NO! It's the same thing with showing how your OC maintains their fit body or nice face! You gotta show how they became that strong and powerful too! 

IT'S OKAY IF YOUR CHARACTER IS A WIMPY BABY THAT CAN'T FIGHT AT THE BEGINNING! It's okay if they lose for the first 20 chapters or so! It's okay if they get their asses whooped and they gotta be saved, or they work together with someone else to defeat someone/a monster! 

Hell, it's fine if they don't become the most strongest demigod/witch by the end of the book! But, uh, you should probably make them a lil stronger then they were at the beginning, you know, so their skills aren't stagnant and shit. 

But anyways, SHOW. THEIR. PROGRESS! Have them be not as great at dueling/fighting, but then over time write about their training or other monster attacks! Unless you're doing a strictly Witch!OC then just, uh, write about them studying or practicing their spells on their own time. Hogwarts doesn't really do any 'training' cuz, you know, it's a school for academic purposes, not war or survival. I'm pretty sure the only 'dueling' practice your OC would get is when Harry and co. start the DA. 

This is just for Witch!OCs but your OC does not need to be an illegal animagus, nor do they have to be a Metamorphmagus. I've read stories where the OCs a Metamorphmagus and... that's it. They're a Metamorphmagus and all they do is change their hair color or some dumb shit. If you want to make them a Metamorphmagus then at least make it somewhat relevant to the plot???

Okay now moving on. I don't know why, but some people just have a weird obsession for making their OCs be amazing singers like—

Sweetie... nobody cares if your OC can sing, we can't even hear it. WE ARE READING A BOOK. Plus, singing isn't even relevant in Harry Potter or Percy Jackson. If you're OC's a child of Apollo, then yeah I guess you can make them a good singer, but I don't really wanna read about them belting out into a song every goddamn chapter. 

PERSONALITY: 

The Mary Sue... honestly doesn't really have much of a personality. And if she does, it's a terribly written one. Mary Sue's personality is so terribly written that she doesn't even seem like an actual human being. Her character's moreso defined by her beauty, power, love interests, and shit. 

Hell, she could have an awful personality, and people still flock to her! She's 'brilliant', 'funny', 'caring', 'sweet', etc. She's pretty much perfect, with no actual flaws whatsoever. When authors do give her flaws, they're dumb things like 'being clumsy' or 'shy'. Everybody loves her for the most dumbest reasons too, what the fuck. 

She's just so 'different' and 'quirky' and 'NoT LiKE oThER gIrLS 🤪' OF COURSE EVERYONE JUST ADORES HER AND THEY DON'T EVEN NEED A REASON WHY! They don't question her, she's always trustworthy, anyone who doesn't like her is an evil bitch who everybody hates, and she can't be corrupted no matter what! Wow, she's practically like a real hero who always prevails! So awesome! 

Oh and more importantly, she's an edgy BaDaSS qUEen! She acts like she's tough shit, mistreats everyone around her, violent, puts people 'in their place', but does anyone ever call her out on this? NO! Because she's the super lovable, kind, caring MC everyone loves!!!

Dear fucking gods, I think it's the Mary Sue's personality that I hate the most. They're always such shit, ugh. 

Like I've stated back at the "Creating Your OC" chapters, give your OC positive and negative traits. Give her actual flaws that can harm her or the people around her. The flaws need to have an actual IMPACT for fucks sake! AND STOP WITH THE GODDAMN "i'm shy and clumsy uwu" BULLSHIT, THOSE AREN'T REAL FLAWS!!!!!!!!

You gotta actually develop your OC, give them some character growth! Stop making them the same person as they were in chapter one, that's so lame!

RELEVANCE TO THE STORY:

Oh the Mary Sue has LOTS of relevance! She's a very important character! I mean, just look at all the achievements she's made: 

(If it's PJO)

- she defeated Mrs. Dodds

- she defeated the Minotaur

- she joined all the quests even though it's THREE PEOPLE ONLY

- defeated Antaeus

- defeated Hyperion 

- fought Luke/Kronos

(if it's HP)

- she fought against Professor Quirrell

- faced the Acromantulas

- killed the basilisk and defeated Tom Riddle

- won the Triwizard Tournament

- created the DA 

(you get the point)

Wait... waaaaaiiiiit a second. Huh, these achievements actually seem familiar—OH YEAAAAAHHHHHH! THESE ARE THE ACHIEVEMENTS ALREADY DONE BY OTHER CHARACTERS IN THE CANON BOOKS! 

BUT YOUR OC IS SUPER SPECIAL SO IT SHOULD BE OKAY IF YOU PASTE HER INTO THESE SCENES AND REPLACE SOME OF THE CHARACTERS WITH HER, RIGHT?

NO IT IS NOT FUCKING ALRIGHT! You should never have your OC steal someone else's spotlight, especially if nothing from the scene is actually different than the canon books (other then you replacing someone else's name with your OC's 😒)

The Mary Sue's got zero relevance to the story. Like seriously. Mary Sues are not only copy-pasted into every event in the books, but they steal the spotlight from other characters in order to make themselves look more important and "special". 

If you were to remove your OC from the story, would the plot be an almost exact copy of the originals? Most fucking likely! You wanna know why??? BECAUSE YOUR STUPID FUCKING MARY SUE IS JUST COPY-PASTED INTO EVERY SINGLE EVENT, BUT BRINGS NO FURTHER RELEVANCE! THE BITCH IS USELESS! UNIMPORTANT! JUST SOME DUMBASS PRETENDING TO BE THE MAIN CHARACTER! HER PRESENCE IN EITHER SERIES BRINGS NO DIFFERENCE TO THE ORIGINAL BOOKS! 

Give her her own fucking story, you guys! Stop adding her in every plot point, stop having her steal people's lines, and stop having her steal people's actions too! 

YOUR READERS AREN'T DUMB! THEY CAN TELL IF YOU'RE TRYING TO MAKE YOUR SHITTY CHARACTER LOOK IMPORTANT! IT'S PRETTY FUCKING OBVIOUS WHEN YOUR OC JUST STEALS PEOPLES' SPOTLIGHTS! 

Make. Some. Original. Content. PLEASE! Since you'll be making a fanfic, obviously not everything about your book's going to be 100% original since you'll be adding aspects from Harry Potter and/or Percy Jackson. But your book should not be 99% content from the original books, and then 1% of your own ideas. 

Alright, that's enough for today. I'm tired af right now, and I think I got most of my points down. This turned more like a rant rather then a how-to, but oh well!