The Second Battle of Byss was a battle between some bounty hunters, the CIS, the Republic, and the Catpire. The Catpire was holding the planet, and did a good job of doing so. Because it was part of Palpatine's plan, he wanted the Catpire to win. He cloned some of their best cats and KDY made more ships for them. Soon, there was a second fleet at Byss. It mostly was stationed to defend Kuat, but in this case it was used here.