Well, the plot could involve a magical artifact in the 'Young Justice' world that has the power to pull characters from other dimensions, and it accidentally brings Subaru in. The members of Young Justice are initially skeptical of Subaru, but as they see his determination and his ability to keep coming back no matter what, they start to trust him. They could then combine their powers and skills. Subaru's knowledge of magic from his world could be used to enhance the team's capabilities in fighting super - villains.
In a 'Re:Zero' and 'Young Justice' crossover fanfiction, perhaps there is a threat that spans across both worlds. The 'Young Justice' team discovers that the source of this threat has something to do with the Witch Cult from 'Re:Zero'. Subaru, being familiar with the Witch Cult, teams up with the heroes. He tries to guide them through the complex and often deadly situations that the Witch Cult presents. Along the way, the Young Justice characters teach Subaru about their world and values, leading to a mutual exchange of knowledge and growth.
One possible plot could be that Subaru from 'Re:Zero' somehow gets transported to the world of 'Young Justice'. He might initially be confused but then use his 'Return by Death' ability to his advantage. For example, he could help the Young Justice team in battles by being able to predict enemy moves after dying a few times. His unique perspective on life and death could also influence the team's moral decisions.
Definitely Subaru from 'Re:Zero'. His 'Return by Death' ability makes him a really unique character. In a crossover, seeing how he interacts with the super - powered heroes of 'Young Justice' would be fascinating. Also, Robin from 'Young Justice' could be interesting. His detective skills and leadership could contrast well with Subaru's more impulsive and desperate style of dealing with situations.
One possible plot could be that a common enemy, like a powerful interdimensional villain, forces the Young Justice team and the Avengers to team up. They start off distrustful of each other, with the Avengers seeing the Young Justice members as inexperienced kids and the Young Justice team thinking the Avengers are too rigid. But as they face the villain's various attacks, they gradually learn to work together. For example, Superboy could team up with the Hulk in brute - force battles, while Robin and Iron Man use their intelligence to figure out the villain's weaknesses.
Well, one possible plot could be that Supergirl is somehow transported to the Young Justice universe. Maybe there's a dimensional rift caused by some villain's experiment. She then teams up with the Young Justice team to stop this villain from causing more chaos across different dimensions. They could learn from each other's skills and powers along the way.
Well, the plot could involve Ben Tennyson and the Young Justice team teaming up to fight a common enemy like Darkseid. Ben could use his various alien forms to complement the powers of the Young Justice members. For example, Heatblast could help Superboy when dealing with cold - based threats.
Another plot could involve the Pleiades from Overlord. They end up in Re:Zero and are mistaken for some sort of magical spirits. Subaru tries to enlist their help in his quest to save Emilia. The Pleiades, with their combat skills and unique abilities, could change the power dynamics in the Re:Zero world and also introduce new technologies and magic concepts from Overlord.
A cool plot could be a time - travel related crossover. The Young Justice team travels back in time and meets the younger versions of the Justice League members. They have to work together to stop a time - traveling villain from changing history in a way that would destroy the future. Or perhaps there's a magic - based crossover where a powerful sorcerer is causing chaos. The Justice League, which is more used to physical threats, has to team up with the Young Justice, some of whom have magic - related powers, to defeat the sorcerer.
One idea could be that the Young Justice team gets accidentally transported to an alternate dimension where the Justice League has turned evil. The Young Justice members then have to figure out how to reverse the situation while also evading capture from their once - heroes. Another could be a time - travel plot where the Young Justice team travels back in time and teams up with the early days of the Justice League to stop a threat that was thought to be long gone but has resurfaced in their own time. A third idea is that a powerful new villain emerges who can only be defeated by a combined effort of the Young Justice and Justice League, but first they have to overcome their differences in fighting styles and leadership.
Maybe it's because your character fits well into the alternate storylines or has unique traits that make for an interesting crossover.
One interesting plot could be that the Young Justice team gets accidentally transported to the Avengers' universe. They initially face misunderstandings as the Avengers are suspicious of these new, young heroes. But then they realize they have a common enemy. For example, a powerful villain is trying to take over both universes. So, they must combine their skills and resources to stop the villain. The Young Justice members' unique powers and the Avengers' experience would make for a great dynamic.
One possible plot could be that Naruto is somehow transported to the Young Justice universe. He teams up with the Young Justice team. Naruto's unique jutsu skills like the Rasengan could be used to fight the villains in the Young Justice world. Maybe they face a common enemy that requires both Naruto's ninja abilities and the superpowers of the Young Justice members to defeat.