Château des Romances

The Château des Romances is the end dungeon of The Night Country and the Heroes of the Seven Worlds. It is brought in this world by Tarsa for Est's plan, and originally belongs to Gilgorn in place of Grand Noah. It has been brought in as a starting point to spread the "Land of Night", and is the environment for the last five chapters of the Collab.

The castle is summoned by Musette during chapter 7 by using a brainwashed Tarsa and prionners in the depths of Grand Noah to channel the power needed to bring it in, even if it is not fully ready. As Novissa and Lest are present near her, they're both brought in directly in the deepest part of the castle during the summoning. Musette steps away while Nightmares appear, threatening to overwhelm the group who is saved by the party of Lars, Rovissa and Daimyokai.

The outside of the castle and its main floors are showed in its dark glory at the beginning of chapter 8, as a large team of Kazuya, Hakunen, Magatsu, Lauratt, Rigeo, Lampas, Dream Fox and Mukuro steps in the front before getting greeted by Nightmares. As they search for Fulbeua, they are blocked by a barrier that needs to be deactivated first. In the kitchen, they meet a nightmare who's ready to tell them where the switch in exchange for a little energy from one of the males. Afterward, the party comes face to face with Fulbueua herself and attack her in hope of getting information about the gate location. However, Musette steps in and asks Fulbeua to deal with the intruders appropriately. As conflicts rise between the two of them, the party uses the opportunity to run away. As they think they managed to escape the throne room, Myusca, Nemea and Vinum appear to chase them, with Vinum teleporting later again to block the exit. The party is forced underground, and fight Vinum who is alone.

The basement is explored during chapter 9, as Lars and Novissa's group are successfully pushing back hordes of Nightmares. As they explore the underground, they get regularly chased by Mysteltainn, Ogretooth and Executioner. In the process, they run in nightmares raping magical beasts, disgusting the group. Eventually, as they run away from the succubi, they end up running into Kazuya's group as the latter is fighting Myusca, Nemea and Vinum with the support of Luka and his allies. They are forced to fight Mysteltainn while her sisters get engaged by Luka's allies.

As the situation gets more frantic, Myusca ends up trapped, forcing Vinum to negociate with the lead heroine to free Myusca in exchange for the succubi's retreat, and Kazuya use the opportunity to have Myusca transfer the seal she got by killing their world's hero to Luka. After the heroes formally introduce each other, Rigeo tells the party about the lord of the castle, Gilgorn, who hid in the basement of the castle. The party decides that they can as well recruit her in the process for additional support.

After descending to Gilgorn's room thanks to Lampas' vines, they face the Demon Lord herself who think they're Nightmares here to toy with her. The party beats her, and when they ask for her help, she asks them why they didn't tell her first although Rovissa remarks that they did.

The party then have Gilgorn bombard the castle with Rovissa's support, bringing the attention of even more Nightmares to the group. After a long bombing, the party attacks the castle and notices important signs of space-time distortion. They're also surprised to be greeted by apoptosis, save for Promestein who remarks that it is natural for them to spawn as bringing in the castle created a cross-world contact. They're also surprised to see some of equipment from Lars' world lying around, and decide to keep their eyes open should more equipment from other worlds be scattered around. As they progress, they find out a note from Dr Yui (a scientist from Kazuya's world and comparable to Promestein) telling them that she sent some equipment.

They also face and beat Musette, Bell and Lyla, forcing them to retreat and give up temporarily on their plan of world domination. When the Cursed Sword Trio steps in again, the heroes are supported by the Lilith Sisters (Alice route) or the three Second Generation Seraph (Ilias Route), clearing the way for them.

After a long marathon of nine impressively long floors, the party meets Fulbeua again standing on the throne that blocks the way to Est, the queen of dreams. They face her again and successfully beating her down before saying that it's probably destiny that brought all the heroes here. Fulbeua herself sneers upon hearing that remark. The next instant, Kazuya ominously tells Luka that "she's lying".

The party eventually reaches the room and sees the White Rabbit, who tells them that the other version of her they have to free is in the room right next to her. When Luka hesitates, Kazuya calls out the "White Rabbit" on her trap, and forces her to reveal herself as Daji. The party then beats the nine-tailed kitsune, who opens them a portal to the "Land of Nights" where Est is waiting. However, more Nightmares spawn in to attack the party before they can step in. Fortunately, Tamamo No Mae/Raphaela steps in as the "Land of Nights" is a threat that they can no longer afford to ignore.

When they finally reach the "Land of Nights", the party is shocked to see all those succubi raping men who fell in Est's dream, but they're determined to bring it to an end. Eventually, they meet Est herself, who tells them that she did all that simply for the sake of pleasure. The party then engage her in a fight. However, as a Nightmare, she feeds on the pleasure used to attack her, and she knocks out everyone save for the seven heroes bearing the Proof of Collaboration. The party then beats her once and for all and close the portal. Est is happy she got to enjoy such fine pleasures, and asks the heroes if they did enjoy it too. In any case, she bids farewell and leave the party, saying that she hopes she will get to taste more of those pleasure soon.

In the post-collab, it's revealed that the castle is still accessible in Grand Noah, although only to the heroes as they have a connection to the place. Gilgorn and Fulbeua are waiting there to be fought again and recruited, and the castle can then be explored to finish recruiting Nightmares and to get other special items.

Trivia

 * "Château des Romances" is French for "Castle of Romances"