The hero is an Expy of Krillin (or at least based on him).He just as much of a Woobie as Krillin, his 'canon' wife looks almost like Android 18, Krillin's wife (and if she was a Tsundre she would fit 18's characterization like a glove), and the hero's relationship with his closest friend started off pretty rocky, much like with Goku and Krillin.
The twins are not children of the main characterThe day/night cycle is pretty damn explicit. The time between "hero reunites with wife-to-be, gets married" and "children born" is a couple of weeks, two months on the absolute outside for the grinders. The only reasonable conclusion is that whichever wife Hero chooses, she's already at least seven months pregnant (presumably by a Zenithean).
Debora's Rich Bitch nature is directly connected to having Spoiled Sweet Nera as her "perfect" sister.Nera has elements of a Purity Sue to her: practically everyone who knows about Nera talks about how sweet, wonderful, and perfect she is, holding her in sharp contrast to her older sister. While Debora certainly isn't The Unfavorite, as her parents still care deeply for her and spoil her rotten, there are hints of them wishing she was more like Nera. No doubt Debora is keenly aware of this. Note how she claims that Nera's suitors are actually interested in her; this could be denial, or pretending that she isn't aware that everyone prefers Nera. She's definitely spoiled, but to a certain degree beyond that her nasty behavior is an act, pretending she isn't hurt by the knowledge she's not nearly as beloved as her dear, sweet sister. To acknowledge it or attempt to change would be admitting defeat and conceding that her sister is superior, something Debora's far too prideful to ever stoop to.
Debora had quite a few reasons to propose to the hero:
Flora and Nera are different people.The difference? Flora was an only child; Nera has an older sister. Alternately...
Debora existed in the original games, but...Debora was born in all of the games, but died due to Diabolus ex Machina before Briscoletti could do anything to help her. When Diabolus ex Machina was dialed back in the remakes so that Bianca could live happily without marrying the hero, it weakened it enough that Debora got to live.
Future remakes will add another candidate for the Heavenly Bride.Because Debora set a precedent. Adding more brides will be an easy way to convince players to buy the games again, and will cater to other interests — just as Debora is meant to catch the eyes of Tsundere lovers, the new girls will be designed according to whatever's popular at the time. Possibilities include:
Future remakes will make it so that Bianca arguably ends up happier if she doesn't marry the hero.The original had her hit by Diabolus ex Machina if you didn't choose her. This was toned down in the remakes, particularly the DS version, so that players wouldn't feel as guilty marrying Flora/Nera or Debora instead. Following this trend, future remakes will put forward the possibility that she arguably ends up better off if she doesn't marry the hero. Nera already demonstrates the logic behind this — if she doesn't marry the hero, she still winds up Happily Married and is spared all of the trauma, tragedy, and trials that the hero and his bride/family face. Bianca will get a similar happy ending if not chosen, finding someone just as suitable and having a good, peaceful life without all that drama.
Your hero kills the Evil Chancellor.He personally betrays you and Gotha out of his own short-sighted Greed and has your wife kidnapped. Though Rewarded as a Traitor Deserves, he survives his injuries long enough for you and your monsters to come across him. The last words out of his mouth are him begging for your forgiveness, and he is cut short. Alternative Character Interpretation and This Is Unforgivable takes care of the rest.
Bianca is biologically Nera and Deborah's half-sisterWhitey has a bit of dialogue shortly before the marriage segment where he confesses that Bianca isn't really his biological daughter. By extension of logic, all three women have Zenithian blood, since whoever you choose bears the Chosen One. Furthermore, Rodrigo's lineage is explicitly stated to be special, considering the whole deal with Bjorn, so it's probably safe to assume that he's where the Zenithian heritage comes from. However, she can't be his wife's daughter because of her blonde hair color. My guess is that he had a fling with Bianca's mother some nine years before the story began and was told sometime later that she was with child. She would have left Mostroferrato to protect Rodrigo's reputation. After you bring her back for Rodrigo to meet, it's possible that he realizes who she is, and that's why he's willing to give you the Zenithian Shield and finance your wedding even though you don't marry Nera as per the original agreement.