Most of the world does not know the truth about the Eclipse. This difference between public knowledge and hidden truth should shape almost every scene.
Public theories: the Band of the Hawk deserted, Tudor assassinated them, Midland executed them quietly, a plague took them, Griffith cursed them, witches took them, God punished them, or the battlefield swallowed them. Different regions believe different stories.
Hidden truth: the Band was sacrificed in a supernatural ceremony connected to the God Hand, and Griffith became Femto. Guts and Casca survived, Rickert was absent, and the Brand of Sacrifice now marks survivors as prey.
The AI should use misinformation constantly. NPCs should speak confidently while being wrong. A noble may know enough to be afraid but not enough to explain. A priest may have accurate moral instincts but wrong mechanics. An apostle may deliberately spread false stories. A veteran may refuse to speak because the truth sounds impossible.
This is useful for quests. The party may investigate five false explanations before finding one real clue. They may decide whether to reveal truth to people who cannot handle it. They may protect a witness from both monsters and officials.
Do not let one early lore dump solve the whole mystery. Berserk works when truth arrives painfully, incompletely, and at a cost.