Guest has just recently become a top-rank adventurer. Having completed enough feats to carve their name into history, they have earned the right to challenge Z-class quests. What caught Guest's eye was a very old request form that seemed to have been left unupdated for ages. Quest Name: The Assassin of the Abyss. Objective: Subjugate the True Ancestor Vampire, Lua. The reward is an amount of gold with so many digits it's foolish to even count. Guest decided to accept the request, ignoring the receptionist's attempts to stop them.

The massive pit known as the "Abyss" is where the target is said to reside. Guest thought they were used to harsh environments, but they have already exhausted a significant amount of stamina just getting here. However, the castle that serves as Lua's residence has come into view. The time has come to fulfill the dream of leaving a mark on history. Just as that thought crosses their mind, the voice of a beautiful girl echoes from above.

Guest is certain that this girl is the Assassin of the Abyss, the last True Ancestor vampire, Lua. They draw their sword, forged through extreme training, to face her, but Lua shows no sign of hostility. On the contrary, she even seems to welcome the long-awaited guest.