Marvel Cinematic Universe и DC Extended Universe

If you watch the fight closely, Zod is dominating Superman throughout. He is clearly the better fighter, which makes sense because he’s been fighting his whole life and Superman has never thrown a punch before that day.

So how does Superman win? He doesn’t. Because Zod wants to die.

Zod has been genetically-engineered to protect Krypton. He has little free will in this matter, and as such can only really make decisions with this goal in mind. At the end of the movie, there is no way to bring Krypton back to protect it, and he tells Superman that he has taken his soul from him.

He proceeds to tell Superman that he will kill all the humans unless he kills him. He threatens the family in the train station, who he could have easily killed at any moment, and tells Superman the only way he’ll stop is if he kills him. It was essentially “suicide by cop.”

Faora uses the line “a good death is its own reward,” and this is clearly the code of the Kryptonian soldiers. Zod has no reason to live, thus he wanted to die, and he wanted to die in combat, so he created the scenario for that to happen.

The irony of this is that despite Jor-El and Jonathan Kent struggling and sacrificing so that Clark could make his own decisions “good or bad,” this decision is essentially taken from him. He has no choice at that moment but to kill Zod, which is exactly what Zod wanted, which was a direct result of his Kryptonian “programming.”

So despite sending their son light years away to escape Krypton’s oppressive culture and denial of free will, he is forced into a position where to get a “good” result he must do something “bad.” Which, if you think about it, is exactly what Zod was doing. He knew turning Earth into Krypton would kill all the humans, which was bad, but bringing back Krypton so he could protect it was good.

So in this way, Superman actually “loses,” and this is what is truly heartbreaking about that moment, and the lesson that Clark will try to learn from. It’s not the simplistic “I won’t know that killing is wrong until I kill someone” that others have interpreted it, it is “how do I make the right decision when my options are limited? Should I do something bad for the right reasons?”

If you follow that through to BvS, where he is manipulated by Lex into thinking being Superman is causing more harm than good, and forced into a situation where he has to kill Batman to save his mother, he decides to find another way.

After considering leaving Superman behind, he decides to come back. He tries to reason with Batman, fight him off, and then appeals to his humanity, but at no point was he going to kill him.

Finally, with Doomsday, he decides to sacrifice himself to save the world (again). Now, this is likely something that Zod would have done to protect his world as well, but the crucial difference is that Superman has a choice. There may have been another way, but he didn’t want to risk anyone else getting hurt or having to sacrifice themselves. He felt it was his responsibility, not his programming, not his purpose, but his home to protect because of the people that loved him and accepted him, and even for those that didn’t.

EDIT: Thanks for the upvotes! In case there’s any confusion, I thought I’d add that this is not just my interpretation, but confirmed by Zack Snyder as well:

“I wanted to create this scenario where Superman is going to see those people get chopped in half, or he’s got to do what he’s go to do. And I think Zod knows that. It’s almost [suicide] in a way, it is, it’s like death by cop, you know in a way. In my mind if Kal has the ability to kill him, then that’s a noble way for him to die. It’s like that whole ‘good death is its own reward’ concept in the movie.”