A fanfic set in a post - apocalyptic world could be interesting. Crayator and Tannar could be survivors trying to rebuild society. They might have different ideas on how to do it, leading to some conflicts at first, but then they realize they need to work together for the greater good.
You could start by creating a setting for your fanfic. It could be a familiar place from their real - life content or a completely made - up world. For example, if it's a made - up world, describe the landscape, the rules of that world. Then introduce Crayator and Tannar into this setting and start showing how they interact with it. Maybe they're exploring a strange forest full of glowing plants in this new world. And as they explore, they start to have conversations that reveal more about their characters and their relationship.
Common themes could include friendship development. Since they are the focus of the fanfic, the story might show how their relationship grows over time.
I'm not sure specifically which 'crayator x tanner fanfic' are really good. You could try searching on popular fanfic websites like Archive of Our Own. There might be some interesting stories there that other fans have created about this pairing.
One idea could be exploring the origin of Alien X's powers. Maybe there was an ancient alien race that bestowed these powers and the story could delve into that backstory.
One idea could be a story where Spiderman has to team up with his greatest enemies to fight a new, more powerful threat from outer space. This would force him to put aside his differences and find common ground with the likes of Doctor Octopus and Green Goblin.
Another interesting concept could be a story about Naruto visiting Starfire's world. He could be amazed by the different technology and culture there, while Starfire is intrigued by Naruto's ninja skills and his chakra.
Perhaps they could meet at a music festival. Asha is lost among the crowds and Starboy helps her find her way. This leads to them spending more time together, sharing their dreams and aspirations in the music industry. They then decide to form a duo for a special performance at the festival.
One idea could be that Shrek and Shaggy meet in a magical forest that's a cross between Shrek's swamp area and the spooky woods where Shaggy often has his adventures. They could team up to find a special ingredient for a potion that would solve a problem in both of their worlds, like a drought in Shrek's land and a monster invasion in Shaggy's.
One idea could be a story where Luffy and Sanji get separated from the crew during a battle and have to rely on each other to survive on a strange island. They could discover new types of food that only Sanji can cook and Luffy can't resist, leading to some comical and heartwarming moments.
One idea could be that they go on an adventure together in a new, uncharted part of their world. They face various challenges like crossing a big river or climbing a steep mountain. Along the way, they learn more about each other's strengths and weaknesses and their friendship grows deeper.