QUICKLY!: This is more than simply Warriors and Rise of the Guardians! Here is a list of books/movies that I have used in this crossover, as well as whether it is post-movie, pre-movie, or what book it is before/after/between. If you haven't read or seen any of these books or movies, a) try them b) I will guide you through it.
Warriors: After A Forgotten Warrior
Rise of the Guardians: post-movie
Artemis Fowl: after the second book(The Arctic Incident)
Star Wars: The Clone Wars: some time during season 5
Hunger Games: after first book, possibly into the second
Dragon Slippers: after first book
Lord of the Rings: after entire story
Harry Potter: before last book, during the summer before school
The Unwanteds: after the first book
The Inheritance Trilogy (Eragon): after the entire series
Tangled: post-movie
How to Train Your Dragon: sometime after movie (I won't focus on this too much(sorry...))
I may also add The Chronicles of Narnia: after The Lion, the Witch, and the Wardrobe, so keep a look-out. I plan to ask my friend, Celia, if she would write a chapter or something along those lines for me, too. Anyway, this is based on a game I thought up back in 5th grade, as an 'Ultimate Adventure' with many different characters. I would put Percy and the other demigods in, but I don't want the Greek gods to be real this time. Also, I have enough confusion with North from Rise of the Guardians and Artemis having discovered in the first book that Santa Claus is really a member of the People named San D'Klass. Of course, even the People have their myths...
I will work towards getting the next chapter in within a few days- I already have to written out in a journal!