During the Ghost Ship miniquest, Jaster & Co encountered a young adventurer and even fought him two times. Near the end, he tells you that his name is Dorgengoa (an unaware time-displaced young Dorgengoa, due to the Ghost Ship's strange properties)and gives you the Captain's Uniform and his sword, the Dorgenedge, disappearing never to be seen again in the game afterward.
Young Dorgengoa fights alternating his little sword with his Dorgenedge, with the latter doing more damage. He can be dangerous at close distance and can even jump and fall with his sword towards the enemies attacking a medium area and doing high damage. The best strategy against him is to attack him from distance while the other party members will attack him at close range. Once he loses approximately 1/4 of his health the battle will be finished.