If I understand correctly, that if you finish all quests and story lines, then you will be able to jump in time into the future, where you will meet your children and you will train them to war against Raizel?
It's not in the game yet, but you're mostly correct. At the current end of the main story, there will be a time skip event where you'll see things that happen during the time you prepare for the war against Raziel, including your war with other countries and your children getting born and grown up.
