Naofumi realizes he isn't fighting for the kingdom or the abstract idea of "the world," but specifically for Raphtalia, Filo, and Melty. He decides to become a "lord" not for power, but to rebuild Raphtalia's village and create a safe haven for demi-humans. Key Plot Developments
Naofumi exploits Glass's weakness to SP-draining attacks using his Soul Eater Shield. The fight ends in a stalemate as the Wave's time limit expires, forcing the other-world heroes to retreat. Tate no Yuusha no Nariagari Episode 25
Naofumi rescues Rishia Ivyred, who was unjustly expelled from the Bow Hero's party, empathizing with her experience of being falsely accused. Naofumi realizes he isn't fighting for the kingdom