Tropes and examples of this type of character?

I'm creating an antagonist for a story and I think I should examine similar characters before finishing his design. Also, I want characters in my story to be as realistic as possible.

He starts out as a relatively normal kid. He is independent, but a trouble-maker and doesn't like authority. In his early teens, he started to aspire to be powerful and have his own country. He wasn't interested in power to feel important, but the wishes that power can grant him. He wanted to shape the world however he wanted to, so he could experiment with what works and what doesn't. In his mid-teens, he starts to destroy his emotions for the purpose of functioning better. He wanted freedom from his emotions so that he could do whatever he wanted and not feel bad about it. In his early twenties, he had succeeded. He became very cold and calculating. Lying for him became easier than telling the truth.

He began to interact with a political group, and in five years, became its leader. Later, he becomes the president of his country. He starts a war between his country and another to gain absolute power in his country. He orders the killing of anyone who opposes him. Once the war is won, he takes over the other country as well. Over the years, he orders the murder of more than just people who oppose him, don't like him, or don't agree with him. He orders the elimination of anyone who he doesn't want to exist, whether for their attitude, criminality, looks, lack of capability, etc. He eventually plots to start a world war and take over the world. He does this all for the sake of entertainment, rather than the sake of making the world a better place or feeling more important (ego).

The protagonist is a retired assassin who had a previous relationship with the antagonist, as his schoolteacher. He lost his job during the war and enlisted as a sniper. After the war, he began assassinating people for a fee. The story is about how he is given money to assassinate the antagonist, but he feels conflicted because the protagonist had no indication of being a bad kid. He thinks that the antagonist has good left in him, and he tries to get close to the antagonist to bring it out.

It turns out that any sign of good in the antagonist is actually a calculated attempt to convince everyone, and the protagonist, that he has good left in him. The antagonist poses as a well-intentioned extremist and feigns guilt for the things that he did. I have yet to create many aspects of the protagonist. So which tropes apply to the antagonist, and what are some good examples of characters similar to him? I can't think of any characters who are like this.

You should put this sort of inquiry in Writer's Block. Worth noting is that Tropes Are Tools: you should write your story as it occurs to you; the tropes will come much more naturally than if you start from the tropes and try to write a story around them.