The sorcerer Ongbozhin was once a traveller who became trapped in Kaseraksa by the Rakshasa Ravana. He managed to stay hidden for decades before eventually deciding to transition into lichdom in an effort to stay alive. After Ravana's disappearance, Ong began to offer a similar transformation to the human slaves who inhabited the bottle as a way to escape their lives as cattle for the Rakshasa lords. After several centuries, he amassed a literal army of loyal ghouls and cabal of human sycophants.
In the year 158 of the 5th age, a group of adventurers managed to get themselves likewise trapped in the bottle where they met the ancient lich. He offered to assist them if they could free him from the city, but they declined and despite carrying the bottle with them, they chose to leave him trapped within.