Hoping that the seal on the dungeon from wizards long ago is still keeping

Black Key Quest - Wizards, Princes, and Princesses in Singing Island will hear the shouts of Ruba, who worries about the eerie sounds she hears coming from the underground dungeon on the peninsula outside of town, hoping that buy martial empires gold the seal on the dungeon from wizards long ago is still keeping the monsters inside and has not been broken.

1) Talk to Ruba, she will tell you that she needs a brave warrior to explore the dungeon for her.

If you agree to explore the underground dungeon, Ruba asks you to bring back a Black Key from the dungeon as proof of your exploration.

2) Talk to the Wizard Kun located outside of the entrance to the dungeon to be teleported inside to begin your quest.

You can find the location of the Lesser Succubus Queen by reading the mysterious writings on the walls of the underground dungeon.

3) Defeat the Lesser Succubus Queen to receive the Black Key.

Keep in mind the lesser succubus queen is fairly strong; you might need a few extra pots to defeat her. You don't have to be alone to defeat her. However, she will only drop 1 key at a time.