Client: Gumbah (J-7) Bastok Mines
Requirements: Minimum lvl 30
Items Needed: Chaosbringer
Key items: None
Title: Dark Sider
Repeatable: No
Reward: Ability to become a Dark Knight

Previous Quest: None
Next Quest: Blade of Death and Dark Legacy

Walkthrough:
Speak to Gumbah for a cutscene telling you to seek out the Dark Knight, Zeid.
Travel to the Palborough Mines, and go to the top floor (by walking or taking the elevator).
Proceed to the boat back to Zeruhn Mines at (H-8), get on the boat. Pull the lever for a cutscene with Zeid on your way to Zeruhn Mines.
He presents you with a Chaosbringer. He also tells you must satisfy its thirst for blood. Then seek him out again in Beadeaux when finished.
You must kill 100 monsters to satisfy the blade.
Once you kill the 100 monsters, take the blade to Beadeaux for a cutscene with Zeid. You will now be able to become a Dark Knight.

Note:
The game won't tell you when you've reached the 100 kills. You must keep track of your kills.
For it to count as a kill, the finishing blow must be made by a normal attack with the sword. Weapon skills that kill the mob DO NOT count as a kill.
Mobs that self-destruct will not count as a kill.
Kills DO count if you first bring the mob's health down with a real weapon and then equip the Chaosbringer for the killing blow. The use of some skills, even with Chaosbringer equipped, such as Jump, will not count towards the 100 kill count.