Final answer:
The described action in the poem emphasizes Beowulf's heroism by showcasing his unmatched strength and the recognition of it by a formidable adversary, highlighting his valor and might as characteristics of an epic hero.
Step-by-step explanation:
The lines from the poem highlight Beowulf's heroism by describing an encounter where even the "master of malice," faced with Beowulf's formidable strength, recognizes that he has never met a more powerful adversary on Earth. This emphasizes Beowulf's exceptional physical prowess and courage, traits that are essential to the archetypal hero in epic literature. By showing the monster's realization, the poet underscores Beowulf's status as the epitome of a hero within the story, capable of facing challenges that no other man could withstand.