Answer: He has great respect for those who demonstrate courage in the face of defeat.
Explanation: In "Frithiof the Bold", the interaction with Atlé, Angantyr's vassal, demonstrates that Frithiof has great respect for those who demonstrate courage in the face of defeat. Frithiof left Atlé to search his weapons. And when he came back, Atlé as a true soldier was waiting calmly for Frithiof who spared his life.