The quest can be started at lvl 19, but I advise just start at Level 20 because the new skills will only be available atthis level.
1) This quest starts in the town of Gludio in front of the Dark Elf Guild with Triskel. He sends you to the Altar of Rites.
2) Go to Dark Elven Village and use GK to Spider Nest and go walking to the Altar of Rites and talk to Witch Arkenia and she sends you to talk to Guard Leikan.
3) Go to Gludin and talk to Leikan is at the north exit by the Warrior Guild, and tells you to hunt Moonstone Beasts around the Neutral Zone.
4) Moonstone Beasts are in the Neutral Zone and the drop rate is 100%, and you need 10. When you have 10 go back to Leikan.
5) Leikan tells you to find an orc named Calpico who is near the School of the Dark Arts.Calpico is north of the School and has 4 other "goons" with him, if you don't have the newbie Life Cubic buff you should bring some healing potions. They aren't hard but all of them at once can hurt fast.
6) Take the Shilen Tears back to Arkenia in Altar of Rites.Arkenia gives you her recommendation.
7) Go back to Triskel in Gludio and he will give you the last ques item.
8)Then when you are level 20 talk to Grand Master Tobias in the Dark Elf Guild in Gludio also and change to Assassin.