One idea could be that Nightwing has to train the Young Justice team in some new combat techniques. Maybe there's a new threat in Gotham that requires their combined skills to take on. Another could be a time - travel plot where the Young Justice team gets sent back in time and meets a younger Nightwing, and they have to work together to get back to their own time. Or perhaps Nightwing goes undercover in Young Justice to investigate a mole, leading to a lot of mystery and drama within the team.
One idea could be a story where Nightwing has to train Robin in a new and dangerous combat technique. They could face off against a powerful new villain in Young Justice that specifically targets their mentor - protégé relationship.
Maybe there's a situation where a powerful artifact is discovered that has a connection to both Nightwing's family and Starfire's alien heritage. They embark on a quest to understand the artifact's true nature. During this journey, their relationship grows stronger as they face various obstacles and puzzles.
A possible plot could be that Slade has some information that Nightwing desperately needs. In exchange for this information, Slade makes Nightwing go through a series of dangerous trials. As Nightwing progresses through these trials, he starts to understand more about Slade's motives and his own limits. This could also involve some flashbacks to their previous encounters and how they have shaped their relationship.
A plot could revolve around a misunderstanding between Nightwing and Starfire. For example, Starfire might misinterpret one of Nightwing's actions as him not trusting her. This could lead to some tension between them at first, but then they would have to work through it and in the process, their relationship could grow stronger. They could have deep conversations about their feelings and past experiences that bring them closer together.
One plot idea could be that Supergirl, while on a mission in a new city, accidentally crosses paths with the Young Justice team. They initially mistake her for an enemy due to her Kryptonian powers being so strong. But as they get to know her, they realize she can be a great ally. Another idea is that there's a powerful villain who is specifically targeting Kryptonians and the Young Justice team has to work with Supergirl to stop this threat. They might learn new fighting techniques from each other during the process.
Maybe Batgirl is sent by Batman to assist Young Justice on a mission. She has to adapt to their more light - hearted and less brooding approach compared to the Bat - family. Along the way, she forms a special bond with a particular member of Young Justice, perhaps Artemis. They have to overcome their differences, like Batgirl's strict no - killing rule and Young Justice's sometimes more lenient attitude towards villains, in order to succeed.
Another plot could involve Damian being sent on a mission by Batman to infiltrate Young Justice, thinking there might be a mole or some sort of internal problem. But as he spends time with the team, he starts to actually care about them and has to decide whether to complete his original mission or protect his new friends.
Maybe a plot where there's a competition between the two groups. A powerful and eccentric billionaire sets up a series of challenges across the city. The winner gets a large sum of money for their cause. At first, it's all about competition, but as the challenges get tougher and more dangerous, they start to cooperate and combine their resources to complete the tasks. This also leads to some friendly rivalries and new friendships forming.
Another plot could involve Raven being sent to the Young Justice world by some dark force. She has to adapt to this new place and team up with them to find a way back home while also dealing with the local villains. During this time, she could form unique bonds with the different members of the team. For instance, she might find a kindred spirit in Superboy due to their both being sort of outsiders in their own ways.
One idea could be that the Bat family is investigating a strange series of crimes in Gotham. Meanwhile, the Young Justice team stumbles upon a lead that takes them to Gotham as well. They initially clash due to different methods of operation. Batman tries to keep his family in line while also dealing with the young, headstrong heroes of Young Justice.