Set in the cursed town of Alcezon and its surroundings, the player controls an exorcist sister (protagonist Leria, name changeable; big breasts, quiet and mature personality) who fights abominable creatures using normal attacks, projectile magic, and close-range magic. The main quest involves exploring dungeons to investigate and eliminate the source of surging monster numbers. Optional sub-quests appear in town or on the way, with flexible timing—some enemies exclusive to subs, more planned via updates.

Defeat triggers erotic horror scenarios: predation, vore, non-consent violation, absorption, mental domination, breast expansion, breeding/incubation, pregnancy, monster transformation—building on the original with unique depictions, larger dot-pixel animations, detailed standing pictures/UI (including "internal" views of the heroine's state), and gallery mode.

Supporting character: Harnja (support sister handling research, base management, healing). Features New Game+, mod support for protagonist image swaps (e.g., hair color, tights on/off, custom outfits), keyboard/gamepad compatibility, Windows/Mac versions, English/Korean/Chinese support (via language mod), and ongoing updates (latest v1.2.x adds outfits, events, enemies, Korean). Trial demo recommended. Sequel to SiNiSistar; violent/grotesque content (toggleable options). Released April 12, 2025.