Bertha commands Evermore's knights with bravery and fierce dedication, especially in protecting Princess Astrid. Her commitment drives her to confront invading Black Banner soldiers, though she falls to Haru, a hero from another world, and faces execution. She survives this ordeal and witnesses key events after Galeroth's defeat, including Yu's coronation as Evermore's new king. Bertha is fate-bonded to Saki Mishima from the parallel world. As a human knight of Evermore's realm, she fights with her sword.