Breaking into the dark ruins, Chrollo traveled through time.
Count Fandohaiwei, that is Duke Chrollo.
14-Year-old Chrollo Lucilu smiled kindly at Ciel.
Short story, mainly attacking you.
There are other characters trespassing inside, such as Jiadros, Saiki Kusuo, Zhao Li, etc.
I've only watched the anime, so I'm just writing something random without any research.
Concept: Spider Head Hunting Diary