One of the reasons why Cell is my favorite DBZ villain and one of my favorite villains of all time is because of how his powers and personality derives from the DNA of various character. He was the perfect final villain who's existence was the culmination of the story up to that point. The way he went from being motivated solely to achieve perfection to wanting to test the power of his perfection was fantastic and showcased a good deal of his traits acquired from the greatest warriors on the planet. But something I noticed (Which I'm sure others have) that adds to his greatness was the personality traits that showed of in each of his forms:
Imperfect Form - Imperfect Cell is a fan favorite for good reason. He's unique that he was weaker than the heroes, so he had to rely on his wits to achieve greater power and to one up his enemies. He's known to be cautious, sneaky and calculating. Traits that resemble Piccolo the most. Piccolo, as stated by Gohan, tends to assess his opponents before fighting them and wouldn't fight 1 on 1 like he did against Frieza and Dr. Gero unless he knows his opponent, and remains calm unless the situation goes out of control (Like Piccolo against third form Frieza and Imperfect Cell against Future Trunks). This resembles Imperfect Cell when he fought Piccolo himself. Imperfect Cell thought Piccolo was weak, and that he could beat him and even if he wasn't weak knew he can escape via solar flare. After assessing Piccolo and realising he was stronger than expected, Cell didn't panic but remained calm knowing he could escape with the Solar Flare. He even told Piccolo about his story knowing full well that even if Piccolo tricks him, he can still escape.
An overlooked scene that further reflects on not only Piccolo's darker side, but Kami's too is when Cell told Piccolo that it's probably the DNA he has from him that fuels his desire for more power. The way Piccolo looked down in shame when he said that was beautiful because it showed how both himself and his Kami side felt when hearing that and how Imperfect Cell's character's was a reflection of Kami's biggest shame: King Piccolo. King Piccolo much like Imperfect Cell didn't need to achieve his full power but was determined to do so, because his true desire was to cause chaos and panic and eradicate the world completely before Kami and himself would die, so that Kami's position of guardian would be rendered pointless since King Piccolo was pure evil by nature. Cell being a product of Piccolo, reminded Kami of how King Piccolo was a product of him, which was something that Kami was deeply ashamed of. It also reflects on Piccolo's darker side as well because Cell gained power through absorbing people's essence, something Piccolo himself did without caring for the lives of those he absorbed much like Imperfect Cell. Piccolo also felt shame due to him being more good hearted or because of Kami's influence.
Second Form Cell - This stage didn't have as much screen time as his other forms. This form is when Cell began to view himself as a supreme power that cannot be surpassed. He's brash and arrogant as shown when he was mocking Vegeta and claiming himself to be invincible. Cell being able to manipulate Vegeta to the point that he fought for him due to him knowing Vegeta's desire to fight stronger opponents due to Saiyan blood shows how much alike they are, as Cell is the only villain to understand the Saiyans like that as he's part Saiyan himself. Cell knew he could manipulate Vegeta, but panicked anyway because of his belief that no one could surpass him. Much like when Vegeta panicking against Goku, even though he knew he could go great ape. Imperfect Cell would not have panicked in this situation, as shown by him remaining composed during his fight with 16 who was far stronger than he anticipated.
Perfect Cell - He's the most interesting as his overall personality is like a combination of Goku and Frieza. His Goku side shows off in his laid back attitude, and wanting to fight stronger opponents to test his limits being his main desire. This is shown by his decision to host the Cell Games which not only was a fantastic way to show off Cell's Saiyan trait, but being a re-creation of the World Tournament which was a big part of Goku's adventures also shows that it represents his Goku's side more than the other Saiyans. A great/comedic showcase of Cell's similarity to Goku is their leniency to fools like Hercule. His Frieza side derives from his cold/sadistic personality yet elegant/polite mannerisms which cancels out the Goku goofiness/light-heartedness. The biggest showcase of his Frieza side is his desire to see the fear in other people's faces before he kills them, this is much like when Frieza decided to transform to his Final Form to see the fear on the Z-Fighters faces even though he could have easily killed them in his third form. Not to mention Frieza genuine delight in torturing others. And, like Frieza, he views himself as the absolute strongest in the universe and that attaining more power isn't necessary for him, he also panics when others surpass him similar to his second form. The genius of his Perfect form is that his Goku/Saiyan side causes him to be the polar opposite of Frieza when faced with the proposition of someone potentially surpassing him, and overshadows the grander scale desires that his Frieza side would have (i.e Universal conquest) and reflects on how Goku's Saiyan desires overshadows his grander scale desires (i.e Planet's safety). Frieza would not allow his enemies to get stronger, hence why he destroyed Planet Vegeta, but Cell would openly challenge them and give them time to get stronger.
Perfect Cell reflects on the side of Goku that Goku himself fears, the side which can spell doom for himself and others: The side that spares those who can bring destruction to earth due to his nature. If Cell really wanted to, he could've killed everyone and rule the universe but he instead did exactly what Goku would do in his shoes and as a result spelt doom for himself. It was perfect (No pun intended) for the whole passing of the torch angle of the saga, because both Cell and Goku intentionally aided Gohan in fully realizing his potential, which happened due to Gohan's reason to fight being his morals/ideals rather than his desire to test his limits like both Cell and Goku. The fact that Cell holding a Tournament which Gohan believed to be pointless was what made Gohan able to go SSJ2 further emphasizes this. Because Gohan needed a reflection of his father to accomplish it, someone who seemed capable of stopping but who ultimately cannot be stopped by words. This was further emphasised by Goku's decision to stay dead at the end of the arc.
In short, it took an evil Goku to make Gohan realize his potential which speaks volumes for the character.
So yeah, all this and more is why Cell is such a great villain imo.
