Demon Lord's Castle
The Demon Lord's Castle is the residence of the Devildom's ruling family, though at the time of MC's arrival, the only royal family member living there was Diavolo. It was first seen in Lesson 7-2 of Obey Me!'s Main Story, and described by Satan in Lesson 6-19 (OM) as "the most magnificent, impressive structure in all of the Devildom."
According to Mammon in Lesson 6-19 (OM), there are many rumors about the castle. One such rumor is that Barbatos has a secret torture room beneath the castle, and that every night the screams of his victims can be heard.
Another rumor is that behind a huge mirror is a hidden entrance to a secret, underground labyrinth that houses "a monster that feasts on the innards of demons." MC learned in Lesson 7-14 (OM) that at least parts of this rumor are actually true.
As mentioned by Barbatos in the chat A Shortage of Helping Hands, the Demon Lord's Castle is a popular tourist attraction. Guests are allowed to make reservations and receive guided tours of the castle.
- Barbatos's Bedroom(source?)
- Breezeway (Lesson 25-8 Hard NB)
- Diavolo's Bedroom(source?)
- East Hall(source?)
- In the Devilgram The Secret Flower, it was mentioned that this area is off-limits, presumably due to the types of flowers it contains.
- Guest Rooms (Lesson 6-17 OM)
- Main Hallway (Lesson 7-2 OM)
- Stairways (Lesson 7-10 OM)
- Labyrinth (Lesson 7-14 OM)
- Lake View(source?)
- Barbatos told Satan in the Wanderers' Whereabouts video call The Memory of a Brilliant Butler that all the books in the Demon Lord's Castle have a mark on the inside of the spine that only he knows about. However, when MC questioned if this was actually true, he simply replied "Well now, who can say?"
- Vault (Lesson 7-20 OM)
In the Devilgram Demon Lord's Castle Tour, it is implied that the current castle that Diavolo lives in may have only existed for two generations. Diavolo explained that this corridor was designed centuries before the Great Celestial War by a legendary architect well-known for using symmetry in his work, although no one knows his name. Said architect was hired by the Demon King who ruled before Diavolo's father. The King came across a small house designed by the architect and was taken by his work. It is also implied that something tragic happened to the architect, but Diavolo did not expand on the details.
In the same Devilgram, Diavolo explained that the design on the floor of the grand foyer is a magic circle meant to protect the castle. The characters inscribed in the circle are ancient runes. Diavolo also mentioned that all the pillars of the castle get narrower as they get taller.
Diavolo also mentioned that when he was young, he built the gazebo in the courtyard, as well as planted greenery and a stone path around the lake. The lake surrounding the gazebo used to be a pit and Diavolo mentioned that no one knows how deep the lake is, but if one looks carefully, they can see a glowing blue light at the bottom.
As stated by Little D. No. 2 in Lesson 7-10 (OM), "the history of the Demon Lord's Castle is the history of the Devildom itself." The castle is filled with historical artifacts, and valuable items. As seen in the Pop Quiz Absolute Zero, one of these items is a strand of fur from the white wolf of frost flowers.
There are also many portraits and works of art. One of these portraits is of the Demon King, Diavolo's father. This portrait is located in the castle's main hallway, and either sitting beside the portrait or painted in the portrait itself is a crown that belonged to the previous Demon King, whose inscription is etched into the crown's inside surface.
In another hallway filled with paintings, there is a picture of the Celestial Realm, as pointed out by Luke in Lesson 7-10 (OM). Diavolo mentioned that it was painted around the time that he first met Lucifer. This hallway also houses a magical portrait of Helene, and the witch herself is trapped within it.
After the first incident involving MC finding themselves in the underground labyrinth — due to being sucked into Helene's magical portrait — Diavolo warned everyone in Lesson 7-20 (OM) to be careful while staying in the castle, due to there being "a number of items here with suspicious histories."
666 Mysteries of The Demon Lord's Castle
- A mirror at the end of the east hall sometimes can have white hands reaching out for those looking into it.
- A door that opens on its own, no matter how many times it's closed.
- A mysterious handprint outside of a window fixed into the wall that's too high up to be reached.