You could do a crossover between BEN Drowned and Sally. Picture BEN luring people into his haunted game world, and Sally being an unexpected ally to the victim, using her own ghostly powers to try and stop BEN. This would create an interesting dynamic between a malevolent and a more sympathetic Creepypasta character.
One idea could be crossing Slenderman with Jeff the Killer. Maybe they team up to haunt a small town, and the story could focus on the survivors' attempts to figure out their motives and weaknesses. It would be a great way to combine two iconic Creepypasta characters.
A crossover involving the Rake and Ticci Toby could be really cool. The Rake is known for its animal - like savagery, while Ticci Toby has his own unique brand of insanity. The fanfic could explore what happens when their paths cross, perhaps in a dark forest where they both hunt. Maybe they fight over territory or a particular victim.
One idea could be a crossover between Slenderman and Jeff the Killer. They could team up to terrorize a small town in a way that combines their unique horror elements. For example, Slenderman could use his mind - controlling abilities to create chaos while Jeff the Killer goes on his bloody rampage.
One idea could be to have Spider - Man encounter the Slenderman. Picture Spider - Man swinging through the city and suddenly coming across the tall, faceless figure in an alley. Another could be Loki causing chaos in a Creepypasta - like town, using his magic to create creepy illusions. Maybe the Avengers have to deal with Jeff the Killer, who somehow gets superpowers and becomes an even more dangerous threat.
One idea could be a story where the dementors from Harry Potter cross over into the Creepypasta world. They could start spreading their despair in the already creepy and dangerous Creepypasta settings, making it even more nightmarish. Another could be a crossover where a Harry Potter character like Hermione accidentally enters a Creepypasta realm and has to use her magic and wits to survive among the various Creepypasta entities.
One idea could be a dementor - like Creepypasta character that haunts Hogwarts. It could drain the happiness not just of students but also start affecting the very magic of the school. Another could be a character from Creepypasta getting lost in the Forbidden Forest and encountering magical creatures in a much more menacing way than the usual. Maybe a Creepypasta villain who tries to steal the Philosopher's Stone for some dark and twisted reason related to their own strange world.
One idea could be that the characters discover a hidden room in the Creepypasta House filled with old portraits that seem to come alive at night. Another could be a group of friends getting trapped in the house during a storm and strange noises start coming from different corners, like scratching on the walls. Or perhaps there's a mysterious diary in the house that reveals dark secrets about the previous owners and it seems to have a curse attached to it.
Maybe there could be a Creepypasta entity that invades Equestria. Let's say a well - known Creepypasta character like Slenderman appears in Ponyville. The ponies are initially confused and then terrified as they start to notice strange things happening. The MLP characters then have to figure out how to get rid of this intruder and restore peace to their land. It could be a story about how the kindness and friendship of the ponies are put to the test against the malevolence of Creepypasta.
One idea could be a crossover with Supergirl. They could team up to fight a common enemy like Lex Luthor who has some new, devious plan that threatens both Gotham and Metropolis. Another idea is a crossover with the Arrow. The two vigilantes could exchange fighting techniques and learn from each other's experiences in protecting their respective cities.
One idea could be a crossover with a popular fantasy series like 'The Lord of the Rings'. You could have planeswalkers from MTG enter Middle - earth. They might interact with the hobbits, elves, and dwarves. Another idea is a crossover with a superhero universe. Picture a planeswalker with superpowers like Superman or Spider - Man. They could team up with other heroes to fight a common enemy. Maybe a powerful Eldrazi that has invaded their world.
One idea could be a Spiderman and Iron Man crossover. Spiderman could team up with Iron Man to fight a new, powerful villain. Maybe they have to combine their tech and skills, like Spiderman using his web - slinging abilities along with Iron Man's high - tech gadgets to take on an enemy who can manipulate electricity.
A cool 'injustice crossover fanfic' could involve 'Injustice' and the 'Watchmen' universe. The gritty and morally complex world of 'Injustice' would contrast well with the unique and dark 'Watchmen' universe. Rorschach could find himself in the 'Injustice' universe and his uncompromising view of justice might clash with some of the characters there, while Dr. Manhattan's god - like powers could be a major factor in the story, either as a threat or an unexpected ally.