The ultimate feature of Agarest War: The Soul Breed system!
Your choice of heroine in each generation will determine the abilities and appearance of the protagonist in the next chapter.
Each heroine's Affection for you can be affected by a number of factors, such as when she joins your party, and the choices you make during events.
The Affection determines which heroines you will be able to choose from at the end of the generation, but if your Affection is high enough, your child will also have improved stats and additional abilities.
And if that wasn't enough... There are special movies for you to watch for each heroine!