As a wiki for some fun, congratuations on finding a manually-written page of some copyright/left matters.
We offer two versions of the article.
The Live version
Welcome. Well, you asked for why we have two licenses, one free-to-distribute and one bound for fansite use.
Well...err...they don't interfere with each other. At least we don't act to break either of them.
In details, you see... This and that image, yes, the Enyi and Berserker and Heavy Cavalry are all properties of Zynga. And not to forget the quotes are as well.
So what is it to do with the wiki? Yea gaah no wiki is for distributing information. Just that simple.
That means if Zynga urges us the wiki would be closed. Yes but not likely.
That means if Zynga wanna alter the text we need. Yes... more likely.
So another problem, what is eligible to be pulled out from the wiki? If you ask me everything but policies can be copied for another fansite, and only fansite.
Other matters are a bit more complex. But whatsoever nobody can interfer you if you collect picture here. The strict rule is that, none of any materials should be used for cash of that or so. Bad boys, watch for police please.
If you use those things here for things in other games, even if we can't chase you Zynga would. Please be polite.
The Dead Version
We are bound by two licenses because the wiki aims to discover and describe about the game Warstorm, which the materials are copyrighted, similar to most of the online games or games and legal affinities. As is the material referred from Warstorm, Facebook warstorm and all other affilitated sites are strict and absolute properties of them, we would have a deep trouble, in particular, a rejection of existance from Zynga itself if we do not abide the official document, Fansite Kit that was provided back in ages of Challenge Games and is still not expire.
In particular, we could go on a simplified explanation on the material uses on the site. All content cited are currently allowed to be stored on the site, but they cannot be altered and posted just for fun. Users need to either upload the unaltered image or make one which the main content is original enough, or something is highlighted to merely show a purpose (like a gif animation showing the poison effect) (a fake warstorm card, is currently classified as fanart only) Users must clearly state the origin and the changes (if any) made to the photo. Abiding these will reduce our troubles very much.
The main similarities of both license have, is any and all materials must not be used to exchange for any and all kinds of currencies. It is because there are only two copiable kind of materials, one being legal product in Warstorm, another being the comments made by all of us, which is all free. You break CC-by-SA by selling them. No deal.