Nokturnus

"No mortal commands me... I obey only my own dark urge to reduce all to nothing."

- Nokturnus in Dragon Quest VI "Brutal bad-dream demon from another dimension. So strong that he makes Mortamor seem more like Snoretamore!"

- Dragon Quest IX Bestiary

Nokturnus (ダークドレアム, Dark Drium in the earliest Game Boy Dragon Quest Monsters games, Dark Dream in fan translations) is a notable figure and one of the most merciless, powerful and brutal villains in the Dragon Quest RPG videogame franchise. This dreadful figure presents himself as an entity with no master and with the sole desire of returning everything to nothingness.

He originated as an optional super boss within a secret dungeon in Dragon Quest VI  for Super Famicom, and its remake for Nintendo DS. Since then, this foe has had many appearances in the saga; one of his most notable ones is in Dragon Quest Battle Road Victory, where he's the leader of all the final bosses up to DQIX.

History
Nokturnus is first encountered as the demon that the king of Castle Graceskull in the Dream World tries to summon in order to stop The Archfiend. Things don't go as planned, the brutal demon refuses to take orders from anyone and he ends up burning the whole castle. The heroes are returned to the Real World where the castle is already destroyed, its tragic fate can be experienced again and again if the hero enters the well. He serves as the game's most powerful opponent, surpassing even DQVI's final boss in difficulty. Nokturnus resembles a humanoid warrior with a powerful staff/spear weapon.