Who is De Lang?

Step 24 of 26, 35 quests in total. Quests in the same step can be done in any order.

1. 1
   A Deal with the Broker Lv. 30+ Han the Broker Parwen the Ghost Lv. 52+ Parwen
2. 2
   Test from the Head of Zenumist Society Lv. 30+ Han the Broker Test from the Head of Alcadno Society Lv. 30+ Han the Broker
3. 3
   Zenumist Cape Lv. 30+ Han the Broker Alcadno Cape Lv. 30+ Han the Broker
4. 4
   Helping Out Bedin Lv. 35+ Bedin Russellon's Items for Experiment Lv. 35+ Russellon
5. 5
   Getting in the Way of Alcadno Lv. 52+ Bedin Destroy the Roid Lv. 52+ Russellon
6. 6
   An Incident, and the Missing Alchemist Lv. 52+ Bedin Life Alchemy, and the Missing Alchemist Lv. 52+ Russellon
7. 7
   Carson's Experiment Lv. 70+ Carson Maed's Experiment Lv. 70+ Maed Parwen's Lab Lv. 70+ Parwen
8. 8
   Clue Lv. 70+ Carson Han the Broker's Info Lv. 70+ Maed
9. 9
   Dr. De Lang's Friend Lv. 70+ Han the Broker
10. 10
    What Parwen Knows Lv. 70+ Parwen
11. 11
    Dr. De Lang, the Missing Alchemist Lv. 70+ Dr. De Lang
12. 12
    Phyllia's Pendant Lv. 70+ Phyllia
13. 13
    Dr. De Lang's Underground Study Lv. 75+ Phyllia
14. 14
    The Key to the Secret Book Lv. 75+ Phyllia
15. 15
    Dr. De Lang's Secret Notes Lv. 75+ Dr. De Lang's Secret book
16. 16
    The Truth About Dr. De Lang Lv. 75+ Eurek the Alchemist
17. 17
    The Hidden Words Lv. 75+ Alcaster
18. 18
    The Secrets of Magatia Lv. 75+ Alcaster
19. 19
    The Black Magician's Magic Pentagram Lv. 75+ Alcaster
20. 20
    The Brutal Truth Lv. 75+ Alcaster
21. 21
    What De Lang Wants Lv. 75+ Parwen
22. 22
    De Lang's Potion Lv. 75+ Dr. De Lang
23. 23
    The Memories of Humanoid A Lv. 75+ Maed
24. 24
    You are here Who is De Lang? Lv. 75+ Humanoid A
25. 25
    De Lang and Humanoid A Lv. 75+ Maed
26. 26
    Magatia's Alchemist Lv. 95+ Humanoid A