Complex sentence: While only 10 years of age, Astarotte is told that she will need to begin building a harem because when she fully matures, her body will require a regular supply of semen to keep from wasting away, much like a vampire requires blood.
Split into simpler sentences: While only 10 years of age, Astarotte is told that she will need to begin building a harem. Because when she fully matures, her body will require a regular supply of semen to keep from wasting away, much like a vampire requires blood.