It has to be Donkey Kong:
->Was the villain in Donkey Kong where he successfully captures Pauline
->was captured by Mario and put into his cage, where his son has to rescue him
->was put into work at the circus
->tries to capture Pauline again, but fails multiple times
->The person he tries to capture becomes mayor and creates a city entirely dedicated to his failures and a festival that showcases that failure.
->Donkey Kong isn't even good enough to be in Mario Kart now, his son has to be in Mariokart.
Now, from here, you can either take 2 stances, Donkey Kong from the DKC games are the same character, or is Cranky Kong. These are both harrowing for Donkey Kong. Because both are equally bad.
Let's assume you want to say he's the same character, or you just consider it a fresh start for the character.
He stars in the game Donkey Kong Country, where he is the absolute worst character in the game. Diddy is faster, more agile, more fun to play as, has more momentum. The only thing he has going for him, is he can jump and kill big enemies with one hit.
Then in the sequel, Donkey Kong Country 2, he's not even a playable character and is replaced by Diddy and Dixie. Both of whom are even better than Donkey Kong.
Then in the threequel, Donkey Kong's archetype of big and strong comes back. But Donkey Kong is captured again. He is literally replaced by a baby. A crying annoying baby is as strong as Donkey Kong.
Then, I don't even want to get into Donkey Kong 64 and the cluster of characters. But they again go with the big and strong, which is important for later.
Then you get into the Returns series.
Donkey Kong then comes back, and is the worst character. Diddy Kong not only is faster, and more agile. He can shoot a gun, and can glide. Diddy is specifically a complete powerup for Donkey Kong because he is so incompetent.
Then in tropical freeze, the same thing happens but even worse. Dixie has an even better double jump, cranky can pogo jump over obstacles, and Diddy is still there(but nerfed really).
Then, Funky Mode releases. Now, you could say that the returns series is okay, because Donkey Kong is still included. Diddy and Dixie are practically just powerups if you aren't playing coop. But then, Funky Kong comes out, and he can fly with his surfboard, has all of the momentum and strength of Donkey Kong, can pogo stick like Cranky, can stand on spikes, and has twice the amount of health of Donkey Kong. "Bigger and stronger" my ass, you get totally dusted by Funky Kong. Are constantly getting your hoards stolen(which is right in your house BTW), constantly getting kidnapped and imprisoned, and a cool guy who constantly walks around with a surfboard(in the jungle mind you), does literally everything better than you. And he's an accredited pilot too, and a successful capitalist. He literally profits on Donkey King's inability to play the game, just to make a point. Even though, Funky has pretty much has most of the abilities he sells, and can literally play the game better than Donkey Kong.
Donkey Kong is literally the Nintendo jobber. He's not even a playable character in like half of the games that are named "Donkey Kong", and the games that he is playable in, he's the worst character. Everything he does is replaced by other characters, hell, even his barrel throwing was replaced by machines in the Mario RPG's. He's constantly getting himself kidnapped and imprisoned. He is literally useless.