The Corrupt Kusari Naval Forces is the Kusari Navy while under the control of the Nomads
You meet them after you encounter the Corrupt Liberty Forces and run with the order to Kusari. Making friends with the blood dragons is your best hope of serving. Note that before you go to Kusari make sure you have lots of money because their ships are costly but epic. Also you won’t be getting any missions with lots of money after you leave Kusari so make sure you have lots of it when you leave. Trust me you will need it.