Fox would claim the rights over them because they were both mutants and children of Magneto, the villain of most of their films, and Marvel would claim those rights because the editorial history of the characters in comic books is more associated with the Avengers rather than the X-Men. The studios made an agreement so that both of them would use the characters. It was made on the condition that the plots do not make reference to the other studio's properties: the Fox films cannot mention them as members of the Avengers, and the Marvel films cannot mention them as mutants or children of Magneto.[11] Despite this deal, films in the Fox X-Men series did not feature Scarlet Witch.[12][13]