Kamen Rider Knight x Batman

http://img1.ak.crunchyroll.com/i/spi...15692_full.jpg
(Yes, it is a doujin manga. Look it up and see for yourself. :p )

Agito and the X-Men. An Agito (I'm thinking the female Agito, Kana, from the end of the show) is taken over by the Phoenix Force and it's up to Agito (Shouichi) and the X-Men to save her. Subplots include Gills fighting Wolverine over a misunderstanding and Beast helping the G3-X team solve a mystery that threatens the city. One time power ups are the X-Men receiving the evolution of Agito and getting their own Rider forms.

Think about it...

http://img3.wikia.nocookie.net/__cb2...lutionLogo.jpg

Kamen Rider Ouja x Superior Spiderman

Funny. Exactly had an idea for a Kamen Rider x RWBY crossover thingy. It was going to feature an OC person as Kamen Rider Kuuga, already being incorparated in the RWBY universe, being a new student at Beacon Academy and meeting Ruby, Yang, Blake and Weiss and you know, Team JNPR, etc. and he was going to be paired up with Ruby or Yang... :lol Yeah, but I don't think I could write that too good...