Someone on here said it best - 21 was an abomination that should be forgotten. She was someone's Deviant Arc donut steel OC made real. Not only was she an artificial human, but a Majin for some unexplained reason. She was always the center of attention; being protected by 16, only to kill him in all three story lines. It's always revealed that she was modeled after Gero's wife and therefore 16's modeled-after counterpart's mother? What kind of fucking shit is this? Everyone of the main cast gets along with her after all the shit she and her other, evil half did.In
the end, she sacrifices her life to ensure the destruction of that said other half. Thus, cementing her "deserved" status as some brave, selfless heroine.
She serves as nothing but waifubait. That's all her character is and always will be. And if you unironically believe otherwise, you're an autistic, insecure retard who should probably kill himself for the betterment of those around him.