MapleStory 4th Thief Advancement Guide
Night Lord, Shadower Fourth Job Advancement
At level 120, talk to Arec the 3rd Job Thief Instructor in El Nath. Then go to the top-right portal in the Valley of the Antelope in Leafre. Talk to Hellin the 4th Job Thief Instructor who will ask you to bring her a Heroic Star and Heroic Pentagon. After obtaining the items talk to Hellin in Leafre again to advance to your fourth job.
Cygnus Knight Job Advancement