Quest 666

From Ethene
Name To the Depths of Despair 絶望の底へ
Location T. Gran Zedora Kingdom
Coordinates D-8
NPC Agatha アガサ
Requirements Quest 665 Complete
Previous Quest 665
Next Quest -
Rewards (First Time / Repeat)
Experience 24000 P 12000 P
Fame 200 P -
Rewards Demon Swordsman Proof
Demon Swordsman Sword
20 points in every Demon Swordsman Skill
Demon Swordsman Proof


  • Talk to Agatha to start the quest.
  • We gotta find Diesel before all that bad stuff happens and he starts unleashing the Darkness on everyone and everything!
  • There's no telling where he is, so let's ask Villa and see if she knows anything.
  • Hightail it to T. Melsandy and talk to the bread connoisseur, Villa.
  • She needs a pick-me-up from Donk.
  • Turn around and exit the Tavern. Right outside, in the garden, you will find Donk
  • He makes vegetables cocktails... we've come into possession of a garlic-based energy drink.
  • Give it over to Villa and she'll energetically hone in on Diesel's location.

  • He's in Defel Wilderness, near the pyramids. Zoom on over there and find him in the aptly named tomb, "Tomb" .
  • Prepare for a boss fight, then touch the tomb.
  • Head back to Agatha to obtain your Demon Swordsman Proof and complete the quest chain.

The Demon Swordsman Proof increases the rate at which the Wave gauge fills up.