Fanfiction crossovers are fanfiction stories that have characters from other shows in another show's world. An example is fanfiction.net's new crossover section, an exclusive section dedicated to crossovers.
You can't find a Triple Crossover Action option on fanfiction. You have to look up a crossover of 2 of the 3 and some people add in a story. It's usually in the summary that they tell you it's a...
Fan fiction, also called fanfiction, is derivative fiction written using another author's characters and universe. Fanfiction authors write stories about their favorite characters from books, movies,...