Blaze Union explains that Gulcasa's main motivation for trying to conquer the world is to protect the common people from the rulers he thinks are oppressing them. In Yggdra Union, when you finally get back to the capital city of Paltina, all the townsfolk are unharmed.
How is Bronquia going to function as a country at the end of the war? If you found the Transmigragem, the Undines of Embellia are all going to transmigrate and come back to life, and Verlaine is a small enough country that the surviving ruler will probably be able to take care of the administration—so Fantasinia's allies will eventually be okay. Bronquia's power was centralized in Gulcasa, as he changed the form of government from monarchy to dictatorship (for lack of a better term), and between all the Bronquian soldiers killed in the war and Yggdra's massacre of all able-bodied Bronquian citizens between Ishnad and Flarewerk, the Empire has lost something like a third of its population, leaving a lot of people who can't do important things like managing the yearly harvest. All the continental countries but Fantasinia were damaged in their own civil wars, and compared to Bronquia's vast territory, Fantasinia is tiny and probably doesn't have the manpower to lend much aid. Even supposing Gulcasa's legacy and influence can hold them together as a people, how are the civilians going to survive?
Yggdra and Durant are ineligible for the mini-event that points out the mausoleum where Luciana and Aegina's body doubles are buried, which implies that they know the official story that Yggdra had older twin sisters who died as newborns. In Battlefield 43, Yggdra explains that she'd theorized since Battlefield 34 that "Aegina" was actually a pair of twins. The full name of the twin you kill in Battlefield 44 is displayed when she dies because Yggdra has become certain of their identities and knows she's killing her sister.