One idea could be to have a character from Naruto end up in the Cloak and Dagger universe. For example, Naruto himself could be transported there and his unique abilities like the Rasengan would be a shock to the characters in that world. He might team up with Cloak and Dagger to fight against a common enemy, perhaps a group that is trying to steal the powers of both universes.
First, study their characters well. Know their powers, their personalities, and their backstories. For example, Cloak's ability to teleport through darkness and Dagger's light - based powers are crucial elements to incorporate. Then, come up with an interesting plot, like them facing a threat that only their combined powers can defeat.
One popular idea is exploring the backstories of Cloak and Dagger in more depth. Maybe how they got their powers in a different way than in the original. Another could be a 'what if' scenario where they are in a different city dealing with different villains. And also, fanfics often explore their relationship, like a time when they had a big fight and how they reconciled.
First, you need to do your research on both Naruto and Cloak and Dagger. Know the characters, their powers, and the settings well. For example, in Naruto, the different clans and their jutsus are important elements. In Cloak and Dagger, the light and dark powers and the social issues in their world matter. Then, come up with a unique plot. Don't just copy existing storylines. You could start with a situation like a dimensional rift that brings the two worlds together.
A fanfic called 'The Bond of Cloak and Dagger' is also quite good. It starts with their early days and how they gradually come to rely on each other. It's a great read for those who want to see more of their backstory and how their relationship developed.
Overall, Cloak and Dagger stays somewhat true to the comics. Some characters and plotlines are adapted, while others are changed for better storytelling in the TV format. There are additions and omissions, but the core essence remains.
The fate of Cloak or Dagger varies across different comic runs. Sometimes they survive intense situations, while in others, their storylines might take a tragic turn and result in their deaths.