Perhaps Baby Connor gets lost in a world full of villains, and Superman has to use all his skills and powers to find him. Along the way, he realizes how much Connor means to him and the future of the world. He also meets some unexpected allies who help in the search.
In the fanfiction, Baby Connor could be from another dimension. Superman has to learn about Connor's origin and the strange powers he brings from that dimension. This could lead to a whole new set of challenges for Superman, like dealing with interdimensional threats that are attracted to Connor.
One idea could be that Superman discovers Baby Connor has some unique super - powers that are different from his own. He then has to figure out how to train Connor while also protecting him from those who might want to use his powers for evil.
Superman can use his super - speed to quickly move Connor away from any danger. For example, if a villain attacks, he can grab Connor and be miles away in an instant.
One idea could be that they meet in a virtual world where Ironmouse's digital presence and Connor's abilities interact in unexpected ways. For example, Connor is on a mission to understand the digital realm better and encounters Ironmouse, who becomes his guide. They then have to face digital threats together and in the process, form a strong bond.
Maybe there's a plot where a powerful alien force arrives on Earth and starts causing chaos. Superman is having a hard time dealing with it alone as the aliens have some new form of kryptonite - like energy. Catwoman, with her stealth and street - smart skills, discovers a way to neutralize the kryptonite - like effect, and they join forces to save the day.
One plot idea could be that Superman and Supergirl team up to face a new, powerful alien threat that is immune to their normal powers. They have to rely on their wits and discover new abilities within themselves. Another could be a story where they travel to an alternate dimension where their roles are reversed. For example, Supergirl is the more well - known hero in that world and Superman has to learn from her.
One idea could be that Superman and Invincible have to team up to stop an alien invasion that threatens both their worlds. The two heroes could initially clash due to their different methods but then learn from each other.
One idea could be that an alternate - universe version of Superman comes to their world. This could lead to a power struggle as both Supermen have different ideas on how to protect the city. Another plot could involve Lois getting superpowers temporarily and having to learn how to use them while also dealing with her regular reporting job.
One idea could be that Batman and Superman have to team up to stop a new villain who has the power to manipulate time. This would put their different approaches to justice to the test as they race against the clock.
Here's an idea. There could be a powerful magical artifact that surfaces in both cities. It has the power to change reality. Superman, being a man of science, is initially skeptical about its power. Batman, on the other hand, has seen enough strange things in Gotham to know it's dangerous. They have to overcome their differences in beliefs as they race against time to stop different factions in both cities who want to use the artifact for their own gain. Along the way, they also learn more about each other's worlds and form a stronger bond.
One plot idea could be that Superman and Catwoman are forced to team up against a common enemy, like a powerful alien or a supervillain who is threatening both Gotham and Metropolis. During their partnership, they start to understand each other's motives and develop an unexpected bond.
One idea could be that Superman gets transported to the Marvel universe during a freak interdimensional event. He teams up with the Avengers to fight a common enemy like Thanos, who has somehow obtained Kryptonite. Their combined powers and different strategies would make for an epic battle and an interesting exploration of how the two universes' heroes interact.