Miura has said that he wanted Berserk to have a happy ending, so my guess is that Femto sacrifices the entire empire of Falconia to summon the Idea of Evil itself and become its avatar, turning into a literal God. But Guts somehow or other finds a way to kill him which initiates another World Transformation. This causes the Apostles and other Godhand members to disintegrate and become null and void, while allowing those they killed and sacrificed to ascend into Nirvana. The defeat of Demonkind allows Guts and Casca's brands to deactivate, and no longer able nor willing to fight due to his body being wrecked from overuse of the armor, Guts lives a peaceful life with Casca in a remote village while Farnese becomes queen due to those of noble and royal heritage outranking hers dying in Griffith's sacrifice. Serpico is appointed White Phoenix General as Griffith was supposed to be until his imprisonment with Isidro serving as raiders captain, while Schierke starts a witch forest like Flora's near Guts and Casca's abode to protect them.
