Kaj Worras was once a man who was friends with Jack Sparrow's great-great-great grandfather. He often used magic to keep himself alive, thus allowing him to survive even through Sparrow's time. After going into debt, Kaj tried to regain money by playing multiple poker games with Jack, who won all of them, sending Kaj into bankruptcy, losing everything he had except his clothing and weapons. He angrily attacked Jack, but suffered horrible injuries. Some time later, Kaj made a deal with Jolly for revenge, but in the process was turned into a skeleton. He was immediately brainwashed by Jolly, and after years of service, became an Undead General.
Kaj soon became feared by many, but Jolly's second-in-command, with Jolly's permission, made Kaj a Dark Undead General. Kaj became stronger, more agile, and deadlier. He soon became more feared than Jolly himself, and was given complete control over the Undead at Padres Del Fuego. He took part in many invasions, claiming many lives, including Christopher Crane's older brother, James. Over the years of Kaj being under Jolly's command, however, he was overturning Jolly's power over him. Soon, he completely broke free, and started a rebellion against Jolly. He freed other skeletons from Jolly's spell, such as his own second-in-command who made Kaj what he is today. Kaj freed the skeletons on Padres Del Fuego, including General Darkhart himself. Padres Del Fuego became a breeding ground for Kaj's forces, and made deals with groups such as La Mafia, which now has a town on the island. El Sudoron became Kaj's homebase, as well. When one enters the forest, they can locate a secret part of Padres if they can scale the cliffs that the El Sudoron is located at the bottom of. Upon reaching the top of the cliffs, many camps, rivers, and caves will be located there.
If one was to climb the cliffs of El Sudoron, they would come across camps, rivers, and caves. These places are infested with Kaj's elite forces of Dark Skeletons, as well as Fly Traps and Alligators. There are multiple chasms on this pathway, with narrow bridges that are heavily guarded to keep intruders out.Undead Reapers have been spotted here as well, normally guarding the caves. These caves are riddled with pits that drop down into Padres Del Fuego's core, as well as various pillars with holograms of Kaj, who communicates with his forces by using these holograms. His main base is located at the very top of Padres Del Fuego, both the base and bits of forest near it being protected by rocks and other barricades that ensure that the lava spewing from the volcano doesn't hit any of Kaj's territory.