What are some interesting ideas for a Supernatural and Smallville crossover fanfiction?

Well, a cool plot could be that an ancient, powerful entity from the Supernatural world is awakened in Smallville. Clark discovers it while trying to protect the town. He realizes he can't handle it alone and contacts Bobby Singer through some means. Bobby then sends Sam and Dean to help. They initially have a hard time trusting Clark because of his superpowers, but soon realize they need his help. As they battle the entity, they discover it has ties to an old, forgotten lore that involves both the kryptonite on Earth and a powerful demon they once fought. They have to combine their knowledge and powers to defeat it.

The clash of different mythologies. Smallville has its Kryptonian and small - town - hero story, while Supernatural has demons, angels, and hunters. When these two collide in a fanfic, it creates a really unique and exciting world. For example, seeing how Clark's superpowers interact with the magic and weapons of the Winchester brothers.

One idea could be that Chloe discovers a hidden power in Smallville that is linked to her own family's past. Maybe she stumbles upon an old diary in the Kent barn that reveals secrets about a long - forgotten relative who had a connection to an otherworldly force in Smallville. This could lead to her and Clark teaming up to uncover more about this mystery and protect Smallville from a new threat that is drawn to this newly - discovered power.

One idea could be that a vampire from The Vampire Diaries somehow ends up in Smallville. Maybe they're drawn there by the strange meteor - related powers in Smallville. Another could be a character from Smallville, like Clark, having to deal with the vampire lore and politics of The Vampire Diaries' world. It could create really cool scenarios where Clark's powers are put to the test in a different way, like against a vampire's super speed or mind control abilities.

One idea could be that the alien technology from Roswell somehow finds its way to Smallville. The kryptonite in Smallville could have an unexpected reaction with the alien biology from Roswell. Maybe the characters from Roswell come to Smallville in search of a new energy source and end up getting involved with the local mysteries and the Kents.

One idea could be that Batman visits Smallville to investigate some strange technology that has been showing up in Gotham and has ties to LuthorCorp. He teams up with Clark Kent, who is still in his early days of understanding his powers. They could have a cool dynamic where Batman is initially suspicious of Clark but then realizes he's a powerful ally.

Perhaps there could be a story where Lex Luthor somehow gets hold of some of Arrow's technology and Clark has to work with Oliver to retrieve it. They would have to combine their skills, Clark's superpowers and Oliver's archery and combat expertise.

Perhaps in the fanfiction, there's a time - traveling aspect. Barry's time - traveling experiments go wrong and he ends up in Smallville during Clark's high school years. They have to figure out how to get Barry back to his own time while also dealing with a villain who is trying to change the future by targeting Clark in the past. This could involve both of them learning about each other's powers and how to work together effectively.

I really like 'Crossroads of Krypton and the Hunting Life'. In this fanfiction, the writers did an amazing job of bringing in the mythology of Smallville and Supernatural. Dean and Sam Winchester end up in Smallville and get involved with Clark's world. It's full of action and some really cool character moments. It shows how the different powers and skills of the characters from both shows can work together or clash in interesting situations.

One idea could be that the kryptonite in Smallville starts to affect the mutants in strange ways. Maybe it suppresses or enhances their powers in unexpected manners. For example, Wolverine's healing factor could be slowed down by kryptonite exposure, leading to a real threat when he gets injured. Another plot could involve Lex Luthor getting his hands on some mutant DNA and trying to create his own super - soldiers, which would draw the attention of the X - Men. They could team up with Clark Kent to stop Luthor's evil plans.