A compelling feature for a game or story with a title like would be a "Corruption & Extraction" Meta-Minigame.
It leans into the "Stealing" aspect of your title while playing with the file-extension theme. It turns the harem members from static prizes into active participants in a heist. Stealing a Monster Girl Harem.rar
Instead of just winning a battle, you have to strategically "extract" the harem members during high-stakes infiltration missions. A compelling feature for a game or story