Antagonists are one of my favorite characters. Besides creating the protagonist and his motley crew, I love chasing the antagonist around and finding out who he is.
Chances are the tyrannical government countering your resistance group is going to be a huge force. More than likely, your protagonist isn't going to be dealing with the head honcho. Your main source of conflict for your protagonist is going to come from characters like Darth Vader and Kylo Ren, the second in command, but the right-hand man.
In that case, you need to single out the best antagonist to conflict with your protagonist. It will be much easier for your readers to connect with and hate a single person than a huge body of obscure people. Ask yourself these questions:
Which antagonist will have the most potential conflict to throw in the way of your protagonist?
Which antagonist has the most to lose?
Which antagonist has the most conflicting goal?
The thing that made the Nazis and the Gestapo some of the scariest and most deadly foes during WWII? It wasn't just that they had overtaken France, Holland, and Belgium in a single blow each. Nor was it that they had the largest numbers, or an incredibly huge goal.
An Admirably Intelligent Foe
All the while the SOE thought they were playing a terrifically brilliant game with the Gestapo in France, the Germans were always one step ahead of them. They were playing the game right back with the SOE and they British didn't even know it.
In her book A Life in Secrets, Sarah Helm tells the story of an SOE circuit in Paris who's wireless operator had been captured by the Gestapo. Instead of simply throwing away this opportunity, they used it to get inside the SOE and find out what other circuits were operating in and around Paris. They pretended to be the operator and fooled the entire French Section of the SOE for quite a long time, with the help of a double agent they had planted in the SOE.
That is how perfect your villain/tyrannical government must be.
1. He is always one step ahead of your protagonist.
2. He knows everything before the protagonist does.
3. He's bigger, stronger, and wiser.
And here's where the line should be drawn between your hero and your villain.
Antagonist's Actions vs. Protagonist's Actions
Their goals could be one in the same, the antagonist's goal could even be an honorable one.
The way your protag and antag go about fulfilling their goals is what separates them. What they DO is what defines them.
Your hero must be separate on the moral level. The Nazis were fighting for world domination, for control, for power. The Allies for freedom, for human rights. These are pretty black and white issues, but your protagonist's and antagonist's goals must fall under one category or the other. And the antagonist/tyrannical government must have the upper hand.
Humanize Your Villain
In her book, Code Name Verity, Elizabeth Wein veers away from the common Nazi villain. Von Linden is not a cruel, evil, or even violence captor. Wein gives him several admirably human qualities.
He loved Shakespeare and the classics, and discusses them frequently with the protagonist (Has human interests in art and literature)
He talks to the protagonist about his children and how much he loves them (Possesses the same human desires and shows an ability to love deeply and truly)
He is kind to the protagonist and treats her with respect (Recognizes the protagonist as an equal)
These are the scariest, most powerful villains with the most potential to control a hero. Why? Because he engages the hero's, and the readers', sympathies.
The 3 Most Important Traits in Your Antagonist
1. His admirable intelligence
2. His advantage over the protagonist to dominate the story world
3. His humane qualities
The days of the cruel, evil villain are slipping away, despite Hollywood's efforts to bring him back. If you get these three things down your antagonist and your tyrannical government are going to rock your story.
What's your favorite thing about your antagonist? Tell me about it!