Demon King’s Labyrinth

The "Demon King’s Labyrinth" is the Dungeon created by Diablo in Cross Reverie.

Background
As well as the 《Avatar Diablo》 it was made in Cross Reverie, becoming real while being summoned to the "Other world".

In the MMORPG Cross Reverie, there was a system called the《Warehouse》. Since it wasn’t something that was handheld, it couldn’t be used immediately at one’s destination, but it was possible to retain an enormous amount of items with it. A countless number of super-rare items whose acquisition method were unknown, were stored within Diablo’s 《Warehouse》.

In Cross Reverie, a peculiar plot of land would be granted to Players that raised military gains that went over a fixed amount. Diablo constructed that peculiar space into a Demon King-like dungeon. Its location was in the western direction, and was close to Zircon Tower city in the Demon King territory.

Surface and entrance
Within the desert, that building existed as if it were added after the fact. On the triangular structure that looked like a pyramid, a stone door was attached. What protected the door was a lion statue, it possessed the wings of an eagle, and its tail was a snake, it was a so-called chimera. It used Petrification Breath and lightning magic.

The first underground floor:
When all of the monsters on this floor are defeated, a staircase will appear in the back. On the first underground floor, only the monsters’ levels were low, but it had become a searching around quest to find out where in the complex maze the monsters were. Since the location of the monsters were random. Some would be camouflaged into the ground and walls, while there were some that stuck onto the ceiling and fell on top of Players that were passing by.

The second underground floor:
"Transforming Maze" this place is a maze that changes with the passage of time. Monsters also wander about. While worrying about where to go, the wall at the back would open up and monsters would appear.

The third underground floor:
The third floor’s mechanism was a homage to a certain retro game, it was made so that when Slimes of differing color were defeated in order, the staircase going down would appear.

The fourth underground floor:
A place that is like a Volcano, there is sweltering heat and molten lava on the bottom of the cliff, monsters have not been deployed in this floor. challengers must cross a gondola,  the questions of a quiz will be asked, if you get it correct, the gondola will advance, if you get it incorrect, the wire rope will slacken and the gondola will descend toward the lava.

The fifth underground floor:
Place freezing with cold wind and falling snow all the time, 30《White Jägers》level 93 guard that floor, challengers must defeat the monsters or win a dance challenge.

The sixth underground floor:
It was a stage that looked like they were in a forest where vegetation grew rampant. There was even a gently flowing river, 《Grand Cancer》was level 99 guard that floor, it was a top-class monster in terms of sturdiness. Its gigantic pincers could bisect even a knight’s armor. Its movement by means of its eight legs was surprisingly fast, and it possessed a bubble breath that had a poison effect. It was an aquatic monster, but it was stronger when on land. Challengers must defeat him or win a cooking challenge

The seventh underground floor:
(Unknown)

The eighth underground floor:
(Unknown)

The ninth underground floor:
There is a great river, there is a thin path that runs along a cliff. Flying monsters should come attacking. At the end of that floor, a large mid-boss level monster is there, but it doesn’t have a Debuff Resistance.

The tenth underground floor:
Has a moving floor as the mechanism. When stepped on carelessly, it will lead you to a room where a large quantity of monsters awaits. When a mistake was made in the moving floor route selection, they would be dropped into a monster house where there was a large amount of 《Ant Beetle》

The eleventh underground floor:
It is a graveyard where《Death Dancer》《Ghost》《zombies》 and other living dead monsters attack.

The twelfth underground floor:
There is a warning on the door that says "Those who value their lives should leave", this floor it was a vast, spacious cave. The ceiling couldn’t be compared with the other floors, and continued on endlessly. What could faintly be seen was sky. The《Large Black Dragon》level 140 guard that floor, its personality was 《Super Aggressive》, Black Dragons use Acid Breath, its Debuff resistance is high, and it has a barrier that negates damage under a fixed amount.

The Thirteenth Underground Floor:
The Demon King’s Room, on the wall that was grotesquely designed to imitate internal organs, there were skeletal candle stands, and white bone colored candles that were lit. Rose was parked on this floor, she acts as guardian of Diablo's treasures.

Treasure room:
Beyond the door that was back behind the throne, there was a vast space that seemed like it was infinite. It seemed that it was either similar to the pouch that Diablo possessed and was magically connected to a different place, or maybe the space itself was created with magic. Countless stone pedestals were lined up. Enough to think that they continued on forever. Various articles were placed on top of the pedestals.

Items:

 * 《Rose》: Originally a simple emotionless NPC Magimatic Maid, Rose gained sentience when she and the rest of the dungeon were transported to the  other world  that Diablo was summoned to.
 * 《Water Hair Ornament》: It was given to Rose.
 * 《White Cow Statue》: It was a reward for a limited-time event, and its classification was 《Important Item》, has the effect of removing 《Marked Death Curse》. It was given to Lumachina.
 * 《Call of Darkness》: A mantle that bestows 《Fear》 on all enemies. Used by Diablo.
 * 《Curtain of Dusk》. Its effect is Damage Cut for a few seconds. It protects the user from any and all attacks. Used by Diablo.
 * 《Angel’s Feather》: It would transfer the user’s entire party to any location. Used by Diablo.
 * 《Empty Sky’s Dance》: Boots that Diablo equipped after visiting his treasury in Volume 7. They possess a Flight Magic ability but requires MP to use. Used by Diablo.
 * 《Tonnerre Empereur》: A black magic staff Diablo equipped after visiting his treasury in Volume 7. Diablo can mentally command it to transform into a blade, after which the staff opens up in the middle like a pair of scissors, with the left and right sides forming a blade with a gap in the middle that has purple lightning running through it, that shapes into a plasma blade made of light. After it is transformed into a sword, it is called 《Tonnerre Empereur • Libéré》. The weapon has an effect that activates magic or attacks seven-fold at a cost of extra expensing of MP or SP. Used by Diablo.
 * 《Phantom Secret Stone》: Its effect was that for only an instant, he would be able to absolutely evade the target’s attack. Used by Diablo.
 * 《Garuda Edge》: A dagger that increases HP and has a moderate chance to cut away an enemy's physical attack. Used by Diablo.
 * 《Gigantes Mail》: Armor that primarily strengthened his physical abilities. Used by Diablo.
 * 《Supreme Ruler’s Bangle》: Cuts damage received below a fixed value. Used by Diablo.
 * 《Seraphic Sword》: A level 70 equipment. It increases experience gained. Used by Diablo.
 * 《Elixir》: It was called the secret medicine of God. Even serious wounds of being on the verge of death could be healed in an instant, even MP would be completely restored, and any and all Bad Statuses would be cured. Used by Diablo.
 * 《Tempest Arrow》: A standard among standards for bow-users around level 50. It is effective against monsters that could only be damaged by magic. It is also able to invalidate Physical Reduction effects from items like the 《The Hollow of Jet Black》. It was given to Shera.
 * 《Engagement Ring》: Created from Eternal Mythril, in Cross Reverie, it was used to show players who are couples. Diablo originally obtained it from the couples' event in Cross Reverie alongside a second account in order to participate. In the other world, it allows couples of different races to conceive a child. It was given to Shera.
 * 《Holy Grail》: And the residence of the goddess Babylon, who has the power to raise Level, but must supply blood from a virgin. Horn used it as a bathroom since there was no toilet in Demon King's Labyrinth. It was given to Horn.
 * 《Treasure Mini》: An armor that increases speed, raises Magic Resistance and Physical Defense. It has a mini-skirt. It was given to Horn.
 * 《Ignore Mantle》: Strengthens the Hide Skill. It was given to Horn.
 * 《Shadow Knife》: Raises evasiveness. It was given to Horn.
 * 《Layer of Secret Stone》: A SSR full body armor, it has high Physical Defense and Magic Resistance and has the effect of Increase Speed. It was given to Rem.
 * 《Wild Animal's Ring》: A ring that strengthens Summons. MP consumption is increased by 30%, Summon's offense and defense are doubled. It was given to Rem.
 * 《Magic Hands of the Beast》: Gauntlets that Increase Speed. They also increase damage against beasts (wild animals, Demonic Beasts, Summons, etc.). It was given to Rem.