One common theme is the struggle between good and evil. The hero represents all that is good, like justice and kindness, while the villain stands for greed, power - hunger or malice. Another theme can be redemption. Sometimes the villain has a chance to turn good, or the hero might face a moral dilemma that tests his own 'hero - ness'. Also, the theme of sacrifice often comes up, where the hero might have to give up something precious to defeat the villain.
In 'The Lord of the Rings', Frodo is a hero. He has to carry the burden of the One Ring to destroy it and defeat Sauron, the ultimate villain. Sauron is a symbol of pure evil, desiring to rule Middle - earth. Another example is in 'Harry Potter' series. Harry is the hero, facing off against Voldemort, a powerful and feared villain who wants to take over the wizarding world and eliminate non - pure - blood wizards.
Midoriya and Toga. It's an unexpected pairing because Midoriya is the symbol of hope among heroes and Toga is a rather blood - thirsty villain. But if you think about it, Toga's admiration for heroes could be a starting point. Maybe she could be redeemed or at least have a moment of self - reflection through her interactions with Midoriya.
It depends on your perspective. Some might think so, while others might have doubts based on various factors like the hero's actions and character development.