One idea could be that the characters from Teen Wolf end up in the Fate universe and have to deal with the complex magic system there. For example, Scott could try to use his werewolf abilities to control the powerful magical forces in Fate. Another could be a love story where a character from Teen Wolf falls in love with a Fate character, like Stiles falling for a Fate mage. Maybe the Teen Wolf pack has to fight against a common enemy in the Fate world, something that combines the bestial nature of the werewolves with the magical threats of Fate.
A plot could involve a portal opening between the Teen Wolf world and the Fate world. Characters from both sides start to cross over. In the Fate world, the Teen Wolf characters might discover new aspects of their powers. For instance, Lydia's banshee abilities could be enhanced or changed by the magic in Fate. Meanwhile, the Fate characters might be intrigued by the werewolves. They could form alliances to face a threat that is emerging due to the crossover, like a dark force that wants to use the chaos of the two worlds colliding to gain power.
One idea could be that the Servants from Fate end up in the RWBY world and have to team up with the RWBY characters to fight a new common enemy. For example, a powerful Grimm that has some sort of magic ability similar to a Servant's Noble Phantasm. Another plot could involve the RWBY characters being summoned into the Fate universe and having to participate in the Holy Grail War, but with their own unique skills and abilities that disrupt the normal flow of the war. A third idea might be that a mysterious force starts fusing the two worlds together, and the characters from both have to figure out how to stop it while also dealing with the cultural and power differences between them.
Well, one possible plot could be that the characters from Teen Wolf end up in the Shuffle world. Maybe they have to adapt to the unique rules and powers in the Shuffle world while still dealing with their own Teen Wolf - related issues like the werewolf lore and the supernatural threats they usually face. For example, Scott could find himself having to use his werewolf abilities in a completely new way to survive in the Shuffle world, and he might have to team up with some of the Shuffle characters who have their own distinct skills.
In these crossovers, a frequent theme is the struggle between good and evil. The Teen Wolf world has its villains like the Nogitsune, and Fate/stay night has its own antagonists. When the two worlds collide in fanfic, the combined forces of good (including Emiya and the Teen Wolf heroes) have to face new and often more powerful threats. Additionally, self - discovery is a theme. The characters from both universes might find new aspects of themselves when exposed to the other world's concepts and challenges. For example, an Emiya - like character might learn something about loyalty from the Teen Wolf pack, while a Teen Wolf character could gain new perspectives on power from Emiya's magic.
One idea could be a new banshee oc who discovers her powers during a full moon and has to deal with the chaos in Beacon Hills. She could befriend Scott and his pack and use her unique abilities to help them fight off new threats.
Scott would be really interesting. His role as an alpha werewolf could lead to some great storylines in the Fate universe. He could be seen as a powerful being there, and his sense of leadership and loyalty would be put to the test. He might have to make difficult decisions about which side to take in Fate's complex power struggles.
There could be a fanfiction where the Teen Wolf gang travels to a city where the Criminal Minds team is based. They notice some odd killings that seem to be related to a supernatural force. The BAU starts to investigate, not realizing the true nature of what they're dealing with at first. As the two groups interact, there are misunderstandings, like when the BAU tries to profile Scott as a potential suspect because of his enhanced abilities. But eventually, they join forces. Scott shares his knowledge of the supernatural world with the BAU, and the BAU uses their profiling skills to track down the real culprit, which is a powerful supernatural being that has been using human proxies to carry out its killings.
A cool concept for a 'naruto fate crossover fanfic' could be the appearance of the Akatsuki in the Fate world. They might be after the Holy Grail for their own purposes, like using it to gain ultimate power or to bring about a new world order. Pain could use his Rinnegan abilities in ways that would surprise the Fate characters. Also, the concept of ninjas from Naruto world learning about the different classes of Servants in Fate, like Saber, Archer etc., and how they would strategize against them.
One idea could be to have the Servants from Fate interact with the Devils in DxD in a battle royale setting. Maybe the Holy Grail somehow ends up in the DxD universe and all the factions are after it.
One way to find good 'teen wolf fate emiya crossover fanfic' is to check out popular fanfiction websites like Archive of Our Own (AO3). Just search for the specific crossover tags on the site, and you'll likely come across some interesting reads. Many authors create unique storylines that blend the elements of Teen Wolf and Fate/stay night (where Emiya is from) in creative ways.
One popular idea is a crossover with 'The Vampire Diaries'. The werewolves from 'Teen Wolf' could interact with the vampires and witches in that universe. It could lead to some really interesting power dynamics and relationships.