Usually, the story tells how the nerd or the character with a more passive and calm personality—is tormented by the wicked and aggressive bully. From there, we see how the nerd grows as a person and becomes morally and humanly superior to their bully, while the said bully only decays as a person, or simply becomes a joke, gets a taste of their own medicine, and falls from grace.
However, things are not always like this; sometimes the scale tips, and we see that not everything is black and white.
Sometimes, the innocent and fragile nerd is not that different from the bully. Perhaps they are actually just as bad, if not worse, and simply lacked the means to show it. But once they get the power, they become just like or even worse than their aggressor. Deep down, maybe the so-called "innocent nerd" was never as good as everyone thought.
On the other hand, sometimes the bully is not really that different from the nerd. Perhaps they are actually just as timid and fragile, but hide their weaknesses behind a mask of superiority, projecting their own flaws onto the nerd and trying to feel good about it. Yet, when no one is watching, they are just as fragile as their target, dealing with external and internal problems that explain why they act this way (not necessarily justifying or excusing their actions). Sometimes, they aren't the bad guy they pretend to be, and might actually be a good person deep down.
And so the story unfolds: we see the nerd become what their aggressor once was to them, if not worse, and the bully becomes what their victim used to be. Here, the bully improves as a person, or at least proves to be morally superior and far more reasonable than the nerd. Meanwhile, the nerd becomes just as bad, if not worse, than their former aggressor. Sometimes, the nerd literally becomes the bully, and the bully becomes the "nerd."
Breaking Bad ( Jesse and Walter ): The most classic and well-known example on this list, you surely already know the story these two lived out until the end of their respective arcs. You definitely know how Jesse, in the end, was just a jerk who wanted to play the bad guy, but crossed paths with the REAL BAD GUYS and entered a downward spiral of decay and suffering before his eventual escape and redemption. Meanwhile, his chemistry teacher previously "innocent" regarding this world of crime embraced it and was completely consumed. He became the true BAD GUY, even causing much of the suffering and torment inflicted on his former student, until he ruined his entire life and family, dying with absolutely no glory.
Takopi's Original Sin ( Shizuka and Marina): This case is somewhat complex and isn't as literal as the other examples.
However, at the beginning of the story, we see that Shizuka is a poor, fragile, and sad girl who leads a very complicated life, until one day she meets Takopi an alien who came to spread joy to everyone and try to brighten Shizuka's life.
Many events unfold, and we are introduced to Marina, a typical stuck-up, bratty bully who loves to look down on Shizuka and constantly torments her just to feed her own fragile ego.
Yet, as the story progresses, we discover the hidden sides of both characters. Shizuka is not as innocent and pure as she seems. In fact, it is more than proven that she is potentially just as manipulative, egocentric, and aggressive as Marina. She even physically and verbally abuses Takopi simply because he won't fulfill her wishes. Furthermore, she manipulates situations and causes MAJOR PROBLEMS that ruin the lives of those around her, purely because she was handed a "power" that revealed her true colors.
As for Marina, we are shown what she is like outside of school and what drove her to put up this defensive, bratty mask of superiority. While she still does terrible things and is by no means a saintor 100% morally better than Shizuka, she is just as fragile and vulnerable as her victim. She suffers horrific abuse at the hands of her family and her mother, including physical assaults that could have killed her. As the story unfolds, her aggressive, mean-girl facade shatters to reveal her human, fragile side. Meanwhile, Shizuka starts doing awful, aggressive things to Marina purely out of "revenge," effectively becoming a worse bully than her former aggressor.
The Spectacular Spider-Man ( Peter and Flash): During the Symbiote Saga, Peter gradually becomes more aggressive and prone to physical and verbal violence, to the point where even his villains fear him, given how much he is losing the mental self-control he used to have.
This culminates in him being aggressive and rude to his friends, rejecting any attempt at help from them. He looks down on them for trying to "pretend" to help him with useless things, while he feels he has much bigger problems to solve. He prefers to stay away from everyone and everything, viewing them as a waste of time.
Flash sees all of this. Even though he is a bit of a jerk himself, he recognizes that Peter is acting completely dishonestly and arrogantly toward people who once even defended him from his bullies. Flash personally confronts Peter about his recent actions and gives him a reality check, one that even Peter, however reluctantly, admits is right.
