Thanks to Liz Shepherd of TheGamers for the inspiration!
One of these theories is somewhat depressing. It involves the not-so-happy secret to Cecil and Rosa’s relationship.
At the end of Final Fantasy IV, Cecil and Rosa are married. They have a son, Ceodore, who is the main character in IV’s sequel game. However, there is a theory that Kain, Cecil’s childhood friend, is actually Ceodore’s father. In FFIV, Rosa is abducted by Golbez. Some have taken this to mean that in that time away from Cecil, Kain took advantage of Rosa, leading to Ceodore’s conception.
However, I honestly don’t see a lot of support regarding this theory, especially considering Kain’s character development as the game progresses. After all, Kain seems to be the type of character who cares far too much about both Cecil and Rosa to do anything like that. So for now, it’s safe to say that Cecil is Ceodore’s father.
This theory would be pretty disheartening if it were true. Cecil and Rosa marry at the end of Final Fantasy IV. It was a perfect storybook ending, as they were madly in love with each other.
Some fans could say that Kain doesn’t attend Cecil and Rosa’s wedding after feeling guilt over adultery:
Kain: Cecil, Rosa. I cannot bring myself to face you both, not yet. I must test myself as you did, Cecil, at Mt. Ordeals. I will train until I’ve surpassed my father as a Dragoon. When that time comes, then I shall return to Baron.
What if he trains on Mt. Ordeals to become a better man, one that doesn’t commit adultery?
Liz assures us that Cecil is actually the father of Ceodore. Plus, Final Fantasy IV: -Interlude- takes place a year after the events of the original game. Of course, Kain would have been with Rosa during the time of the events, and he was away at Mt. Ordeals at the time.