From p. 5 of the Install manual for the Corsair H100i V2,
"• Connect the pump power cable to the
CPU_FAN header on your motherboard.
• Connect the fans to the two connectors
coming off the pump."
The next step is to connect the pump unit to a mobo USB2 header using the cable provided, and then install the Corsair Link software package. This software takes over control of the entire Corsair CPU cooling system, and it uses that USB connection for communication with the pump AND with the two fans plugged into the socket on the pump.
The manual for the Kraken X52 system says in steps 7 and 8 that it has a single multi-wire ribbon cable that plugs into the side of the pump unit. From that cable there is ONE 4-pin fan connector that plugs into the mobo CPU_FAN header. Then separately coming from that ribbon cable is a set of wires with FOUR fan male output connectors on it, and you must use THOSE for the fans on the radiator. After that there are two more connections - one to a SATA power output connector from the PSU, and one to a mobo USB2 header for communication. NZXT provides their CAM software utility to control the Kraken system.
Manuals are useful if you read them.