Sado

Sado is one of the main antagonists of the video game The Hex, a mystery multi-genre game made by the creator of Pony Island. She has one of the smallest followings out of all the characters here due to how niche The Hex is - there isn't even a wiki for it - but still manages to score a spot on here anyway through sheer Vibes alone.

Basic Information
The player first encounters Sado as the boss of the Combat Arena X section of the game, where she tests the skills you've developed over the course of that section and screws with your mind while she's at it, creating a particularly memorable boss fight. After you finish the Combat Arena X section and go through the Secrets of Legendaria section without any signs of her, you're lead to believe that's it, and that's all she's there for...and then she shows up in Waste World and you go "Oh. There's more. Uh oh." And "Uh oh" is about right for her future contributions to the story.

Burton
Mostly black and white with splashes of red, the whole creepy clown aesthetic, the eyeball belt buckler...she definitely has the Burton aesthetic down to a tee.

Clown
Her title in Combat Arena X is Dark Clown Sado, and her theme definitely reinforces the circus and clown theming.

Villain
Directly opposes you in three of the six video game sections, leaves obstacles in one of the three she doesn't directly oppose you in, and makes a cameo at the end as a sort of stinger to it all.

Eldritch/All-Powerful
Her thing is that she's not a fighter, but a performer...and you're part of the act. As a result, her fights all consist of reality-twisting mind games that no other character in the game can match - she grows giant, makes you fight a twisted version of a training dummy, prevents a character from respawning, sends you into a different game entirely, and that's only scratching the surface.

Retro
Like most of the characters in The Hex, she's drawn in an art style meant to harken back to classic video games.

Glitching
Tends to invoke glitches in her wake as a result of her powers. She's even referred to as The Error by a faux arcana card you can find in the sixth and last section of the game, Walk.

Dominating
Her "fight" in Waste World is less of a fight and more of a public execution. Not helping is that Sado takes the time to mess with the player character of Waste World, Rust, after the fact.

Distinctive Voice
Or rather, distinctive voices. The voice blips used for her lines never stay the same for more than one sentence, and once you notice, it's kinda hard to ignore how her voice is constantly changing.

Eye Imagery
Eye on her belt, uses an eye in her first boss fight, and the sign of her handiwork in Walk is a glitchy red eye that serves to complicate the puzzles you have to complete.

Twisted Freaking Cycle Path
Messes with the mind of Rust for no reason whatsoever, and just. Does not seem mentally stable in the slightest.

4th Wall Blurring
Like most of the characters in The Hex, she's very much aware she's in a game, but unlike them, she tends to take more direct action when it comes to the player, giving you a brief jumpscare in Walk and even hijacking Rust's position as the player character during the end of Waste World to force the player to shoot him. In the ending, she's even shown to have bypassed the fourth wall entirely and entered our world.

Mysterious
Exactly how Sado came to be what she is is unclear, and the game offers several answers that are all equally valid. Was she just advanced code gone rogue somehow? Was she created in an act of malice to sabotage the games? There's references to the Devil in Pony Island, if you look around - was she made in a deal with the devil? Who knows!

Urban Legend Aesthetic
The Hex and it's characters are meant to play with video game tropes and the communities around those games, and Sado is no exception, specifically acting as a homage to the typical Creepypasta of "oooooo my game is haunted oooooooo" you'd see back in the 2000s, such as Sonic.EXE and Ben Drowned. If it isn't clear by now, she does that with flying colors.

Animal Theming
Grows a spider body during her boss fight in Vicious Galaxy, and uses spiders to attack as well during said boss fight.

Chaoslord
The most solid motive one can pull out of character is that she does her destructive actions for the funsies. She really doesn't take any of her fights seriously - she even claps when Bryce, the player character of Combat Arena X, manages to actually get through all her mind games.

Theme Song
You can listen to it here.

Suitguy
Do I need to explain this one.