Being a character in You is almost as lethal as being in Squid Game, especially if someone is Joe Goldberg's love interest. The murderous book lover would go to any lengths to keep himself safe, but he found tough competition in Love, Peach, and even milder characters like Theo in the same department.
Squid Game was a test of patience, mental and physical resilience, as well as plain ruthlessness. Every person who participated had traits that were beneficial or disadvantageous to them, and lasting in the game meant being smart and steely, which some You characters could be, and some weren't. Here's how they would fare in the dangerous Korean game.
Marienne Bellamy
Joe's newest obsession had no survival instinct at all. She lived an ordinary life and dealt with addiction, but she had a penchant for associating with the most unsavory characters across the board. Her first husband was Ryan who threatened and abused her, and her second stab at love was with Joe.
Most notably, she entered the lion's den, aka Love and Joe's home, completely unarmed and brought her daughter with her. Marienne would have easily become one of her victims had Love not shown mercy, and nobody really survives on mercy in Squid Game.
Guinevere Beck
Beck's positive and negative traits in You would make her one of the weakest players in Squid Game, mainly because she was naïve and couldn't see trouble right in front of her. She recognized her worst friends like the obsessive Peach, and partners like Joe who would do anything for her but also kill her should they feel like.
She would probably try to be friendly with everybody, not realize the kind of trouble she had signed up for with the game, and maybe die in the first round of Red Light, Green Light.
Delilah Alves
One of the more dangerous characters in You, Delilah would be smart enough to investigate and try to get to the bottom of what was really going on, and maybe even reach the Front Man's apartment and look around because of her nature, but her one big weakness would be Ellie.
Delilah loved her younger sister dearly and would give up her own life to save Ellie's in an instant. This self-sacrificial nature would work against her, and she would probably let Ellie win in the Marbles game in some way.
Forty Quinn
Love's brother could be creepy at times, but his niceness and troubled nature far outweighed that. He needed to be cared for by Love and his family, and had little motivation to do anything and see it through.
He was delicate at most times and he couldn't handle knowing the ugly truth about things, which means that he would probably have a breakdown the moment he saw people dying. With very limited self-preservation skills, the You character would survive up to a point because of his sister only.
Theo Engler
Theo might not be the most lethal character, but he was sharp when he wanted to be. He was observant of his surroundings and could see missing pieces the way he did with the camera footage of Natalie's car with Joe in it.
Being a young college kid, he had the endurance for games like Red Light, Green Light, the Tug of War section, as well as the Glass Tile game, but he could be a bit oblivious too. His teammate would most definitely be Love, and she would betray him to save herself, Joe, and Henry.
Peach Salinger
The Salinger descendant was quite a formidable enemy to have, as was evident from her unwillingness to die even when she was hit over the head with a rock in one of You's biggest twists. She was incredibly clever, and kept up with wily Joe at every step, catching on to his tactics really quickly.
Peach would definitely push others in front of her in the Glass Tile game, the way she threw her friends under the bus, and she would cleverly win the Marbles game by killing someone else off too.
Matthew Engler
The tech whiz had his wits about him, and he had the skills to set up tech traps everywhere to catch out the Front Man and the Guards. He had illegal software at his disposal, and he wasn't afraid to cross boundaries to get what he wanted.
Squid Game also required this kind of brutality, because each person had to fight their own teammates to survive till the end. Matthew had no issues in doing just that.
Love Quinn-Goldberg
Easily one of the most wicked characters of You, there's no doubt that Love would keep her head straight, commit crimes, and take herself to the end of the game by killing as many people as it took. Moreover, there was open killing and murder in Squid Game, so she didn't have to worry about covering up.
Her instinct was to attack people at the slightest provocation, and even without it, so she would feel no qualms about selling people out, murdering them in the dead of the night, or getting ahead in the game. Her baking and confectionery knowledge would also give her an advantage in the Dalgona candy challenge.
Joe Goldberg
Joe may kill for love, but he would also kill to keep himself safe and sound. Like he had killed Jasper to keep himself from being hunted down, he had zero emotional attachment to any human life and easily murdered even loved ones when he wanted to.
Despite Love being the perfect partner for him, he didn't hesitate to inject her with aconite to save himself, which always left him the last man standing. He would win the Squid Game and wouldn't lose any sleep over the horrible things he had to do to emerge victoriously.
Mr. Mooney
This old man quite resembled Oh Il-nam in Squid Game. Mr. Mooney was nowhere near as gentle as him, but he lay the foundation of Joe's killer nature, so it would be no surprise that he would be the man behind the Squid Game too, and relish it.
Mr. Mooney would use his old age to keep people from guessing his part in the games, and people would also take pity on him because of that, all the while pulling the strings from the back and getting out alive no matter what.