Publicly, Succubus Village is considered to be deceptively named, having no succubus inhabitants. It's believed that, every century, an event known as the "Purple Sabbath" takes place, during which succubi flock to the village to rape its inhabitants. In reality, there are several senior succubi disguised as normal human women who transform the villagers into succubi. The inhabitants of the village try to flee before the Purple Sabbath occurs, although some are unable to leave due to poverty or are just unwilling to and want to get raped.
Luka and Alice arrive at the Succubus Village after hearing about it from an old woman within Grangold. There, they meet a prostitute, two farmer sisters, a bunch of men here to get raped, an odd soothsayer, and the suspicious village chief.
They head to the inn to wait overnight. Alice tells Luka the truth behind the Purple Sabbath. Luka wonders if Alma Elma might show up, but Alice doubts it. With her usual lack of concern, the Monster Lord leaves and Luka drifts off into sleep.
Luka wakes up after the Purple Sabbath has started. He rushes around the village, encountering several succubi who try to rape him. He defeats the prostitute Maccubus, the younger farmer girl Mincubus and the older farmer girl Lencubus. He arrives at the village chief's house and can either ask her about the current situation or directly confront her with her true identity.
If he asks her, she recognizes his lack of intelligence. If he confronts her, she reveals her true form. Either way, the succubus chief and the soothsayer reveal themselves to be senior succubi: Succubus and Succubus Witch. They also reveal that this Purple Sabbath is a special occasion, as they plan on reviving Lilith & Lilim, ancient succubus sisters from 500 years ago. The soothsayer exits while the succubus chief tries to extract Luka's semen for the ritual (although greed and lust overcomes her and she says she wants it all to herself).
Luka defeats the chief, then Succubus Witch, but the latter uses the remainder of her energy to revive Lilith & Lilim. They recognize the Angel Halo, the very thing that sealed them, and also realize that Luka is a descendant of Heinrich.
After resealing Lilith & Lilim, Luka tries to assist the fallen men. Alice reappears and uses her magic to revitalize them, also unintentionally unsealing the succubi. The lustful demons state they don't want to fight anymore; they're obviously no match for Luka. Their real plan was to create a haven for their own race (since human women dislike them out of envy and competition). Fortunately, the drained human men are touched by their story and agree to coexist as succubi and human livestock.
In Chapter 3, a succubus named Eva, one of many monsters empowered by Black Alice, attacks the village. She creates the Great Barrier of Babylon, a high-level barrier that elevates humans to maximum sexual excitement to extract large amounts of semen, causing them to ejaculate instantly and mindlessly. By the time Luka arrives, Eva is in the midst of pummeling Succubus and Succubus Witch to the ground. Luka defeats Naccubus (another succubus empowered by Black Alice) and three Imps (who are unrelated), followed by Eva. Although he defeats the one responsible, the Great Barrier of Babylon remains in place; causing Alice to theorize that the barrier is self-sustaining and can only be stopped if it was to lose its power. It is only the efforts of the Unfortunate Monsters—Amira, Pyhar, Diamrem, and Garfunkel—that cause the barrier to cease function and return the town's state to normal.
One month after Goddess Ilias's defeat, Eva has been sentenced to five years of labor. She seems grateful for receiving a minor punishment; noting that five years of labor is preferable to starvation. However, she mentions that once her punishment is finished, she plans to target the mayor and take over the village to make all the men hers.