I wanted her to be strong, tough, powerful, yet not a dirty Sue smiler.

Um...greater details please?

4961865 I don't know. Kindly provide some details so that we may evaluate further.

"Strong, tough, and powerful" could describe a good portion of the Apple family. Powers and abilities aren't what makes a character a Sue. They can contribute to the impression that a character is one, but they aren't enough in and of themselves. Tying to balance strengths and weaknesses like you're making an RPG character isn't the way to go about it.

A character is a Sue when the author treats them like they're special, but the reader can't see why they should be. That's why there are so many debates about what makes someone a Sue.

Let's take two of my OCs, only one of which I've actually written in a published story.

Autumn Wreath is an earth pony maid and hoofservant who works in Canterlot Castle. She has no unique abilities, a fairly mundane life, and all in all just doesn't stand out. When she shows up in a story, it's generally to be the "everyman" character trying to cope with the weird shit that comes up when one spends an appreciable amount of their time in the presence of Equestrian royalty and their friends.

Midnight Silvermane is the last son of a disgraced former noble household, who were cast down after following Luna's descent into dark magic. One of his eyes has been replaced by a magic gem that can pierce any illusion, including Luna's magic and changeling disguises, and it gives him some other perception-based abilities. His special talent lets him use shadow magic (as in shadow manipulation like Shikamaru on Naruto, not Sombra-like dark magic), and he's the leader of a secret organization dedicated to rooting out evil and corruption in Equestria.

Which one's the Sue?

At first glance, Midnight is obvious. He's so edgy that red and black alicorns think he needs to take a step back, right?

Nope, depends entirely on what I do with them.

So Autumn is a mundane pony living a mundane life. I could still have a story where Shining Armor finds her so alluring that he leaves Cadance for her, and Cadance admits she can't compete and lets him go. Unless I played my cards very carefully, she'd come off as a Sue, because what makes her so much better than Cadance? How did she earn that spot?

On the other hand, there's nothing stopping me from giving Midnight plenty of conflict and character development. There are plenty of things that could serve as external challenges for him, though I didn't go into his weaknesses before (as I wanted to discourage the "flawed powers=character depth" line of thought), and just as many to serve and internal conflicts and distractions. The point is, so long as he's always being challenged, nd the audience feels like the challenge is legitimate, he'll avoid Sue status.

So give your OC whatever traits you want. Just make sure those traits never make her life too easy.

4961865

give her flaws.

The most important thing you need to do to avoid being a mary sue is have more negatives than positives. Struggles, anxieties, things that hold her back, things she has to overcome, these will stand out to people reading more than anything positive about them.

Take my OC for instance, he is a very large pegasus, very strong and muscular, a bit intimidating... but every one of my reader's knows him as the following: "A big, shy doofus who is a nervous wreck around mares and in general very quiet in social situations."

Forget how big and strong he is, he's meek. And thats what defines his personality more than anything else.

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4963785

Ya'll need to take a lesson from the best OC, Nightmare Star:

He was banished to the stars for millions of years after he tyraniccaly abused society's principals. He was chased and beaten by his own parents and forced to work in the Rainbow Factory for his misdeeds. But after his banishment, what happened?

He confronted the mane six with all of his wisdom and by virture of the holy Mainshep, he had become something greater. He had become the new leader of all of society.

Celestia herself bows before his greatness. He had gone above the Celestia.

Where there was cold, he brought fire. Where there was darkness, he brought light. Where there was suffering, he's going to bring happiness.

The mane six sought to bring him down, with the exception of Rainbow Dash, who rightly flew with him into the future. She had the right idea. Everyone should love Nightmare Star.

He's brave, powerful, handsome and a King of everything.

...That is Nightmare Star.

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MUH... MUH... MUH MAINSHEP...