Barry Allen, the Flash himself, is obviously very popular. His speed and his kind - hearted nature make him a central and beloved figure.
Iris West is also quite popular. She is not only Barry's love interest but also a strong - willed journalist who often gets involved in the action and helps the Flash in her own way.
Well, for the Avengers side, Iron Man is often really popular. His high - tech suit and witty personality make him a great character to include. On the Flash side, of course, the Flash himself. His super speed and his relatable backstory as Barry Allen are appealing. In fanfic, you also often see Captain America being a popular choice as he represents honor and leadership, and he can have some interesting interactions with the Flash, like discussing different concepts of heroism.
Naruto himself is often a popular character in these fanfics. His natural speed and determination make him a great candidate to master the flash step in unique ways. Fans love to see him combine his Rasengan with the quick movements of the flash step for devastating attacks.
Obviously, The Flash and Supergirl themselves are very popular. Their unique powers and personalities make them central to most fanfictions.
Well, obviously Supergirl and The Flash themselves are very popular. They are the main characters in their respective shows and fans love to write about them in different scenarios. Also, villains like Reverse - Flash are often popular in fanfiction as they add a lot of conflict.
The Flash himself, of course. He is the central character and his ability to time travel is what drives most of the stories. Fans love to explore his different adventures through time.
Naruto himself is often a very popular character in flash Naruto fanfiction. After all, the stories are centered around the Naruto universe. Sasuke is also popular as he has a complex relationship with Naruto. Hinata is well - liked too, especially in stories that focus on Naruto's love interests.
Well, obviously the Flash and Arrow themselves are very popular. Their dynamic, with the Flash's light - heartedness and super - speed contrasted with Arrow's brooding and combat skills, is really appealing. But also, characters like Felicity Smoak are often popular. She's smart and has great chemistry with both heroes, so she often plays an important role in fanfictions.
Definitely Naruto and Flash (Barry Allen) themselves. They are the main characters of their respective series, so it's natural that they are at the center of most crossovers. But also, characters like Sasuke from Naruto can be popular. His cool and brooding nature contrasts well with the more upbeat Flash characters. And on The Flash's side, characters like Iris West could also be interesting in the crossover as they could bring a different dynamic to the story.
Kurt from Glee and Cisco from the Flash could also be a popular pairing. Kurt is known for his fashion sense and his sassy personality, and Cisco is the tech - genius of the Flash team. They could bond over their creativity, with Kurt helping Cisco with his style and Cisco introducing Kurt to some cool tech gadgets.
Harry Potter and Barry Allen (The Flash) are often popular to pair. They both have a strong sense of justice and a desire to protect their worlds. Harry's magical abilities combined with Barry's super - speed can make for some exciting adventures. Another popular pair is Hermione Granger and Cisco Ramon. Hermione's intelligence and knowledge of magic can work well with Cisco's technological know - how.