Rogue/Thief

Thief 1st Job Advancement (Requirement: Level 10, with 25 DEX)
Proceed to the Thieves’ Hideaway at a basement of a cafe in Kerning City. In there, you’ll find the Dark Lord. Talk to him, and you’ll be advance as Thief if you’ve the requirement stats.

Thief 2nd Job Advancement (Requirement: Level 30)
Head back to Thieves’ Hideaway once you’ve reached Lv 30, which is located at the cafe in Kerning City. Go inside, talk to Dark Lord. He’ll give you a letter and you’ve to pass it to the job advancement instructor near Kerning City. After giving the letter, you’ll be given an errand to collect 30 Dark Marbles by defeating the monsters inside. Be careful to stock your potions up before you start collecting the 30 Dark Marbles.
Once you’ve collected 30 Dark Marbles, talk to the instructor, and he’ll award you with a Proof of a Hero. Go back to Kerning City Thieves’ Hideaway, and talk to Dark Lord once again, where then you’ll advance as the Bandit/Assassin

Thief 3rd Job Advancement (Requirement: Level 70)
Go to El Nath – Chief Residence and speak to Arec. After talking to Arec, head back to Victoria Island and talk to Dark Lord which is located in Kerning City. Next, find the Door of Dimension located at Monkey Swamp II and it’ll bring you to “The Path of the Glittering Crystal”. Walk until the end of the path and enter the portal to defeat the wiseman’s dark side to obtain the Black Charm.
Return to Dark Lord and exchange the Black Charm for a Necklace of Strength. Return to El Nath after that and give the item to Arec. Head on to the Holy Ground at the Snowfield (Sharp Cliff II). 1 Dark Crystal is requirred to answer 5 questions to obtain the Necklace of Wisdom. Again, head back to Arec in El Nath and give him the Necklace of Wisdom.
.