connect all of the case fans molex connectors together and run a single molex power from your power supply. with case fans they are either molex powered (bigger plug) that can be sometimes controlled with a fan controler and there are also 3 pin case fans that plug in directly to your motherboard headers
If you want to use the fan controller built into the case, then you will need to run a power line form the psu to the fan controller input, then hook up the fans to the output of the fan controller going to each fan itself. It will be important to identify the type of power connector the fan controller uses. If the fan controller uses the small 3 pin plug, then you will need an 4 pin molex to 3 pin fan adapter. Otherwise, you can connect the fans as suggested in the previous posts.
Although, from reading this review of the case, XION XON-980-BK ATX Mid-Tower Case Review, the case itself will hold up to a total of 7 - 120mm (2 top, 2 side, 2 front, 1 rear) fans and the fan controller can only control up to four fans. Also from the review, the fan controller is only a fan on/off option and has no rheostat to control the fan speeds. This is not necessarily a bad thing as you can have the 3 fans that come with the case hooked up to always run, and then connect the additional fans off the controller and turn them on as you need more cooling.
Can I hook up all of the fans molex connectors together into one long strip and then plug that strip into the power supply? Also some of the fans molex connectors are 4 ports and some only have 2. Thanks!