How does evil manifest itself in Beowulf? / How does heroism manifest itself in Beowulf

          In the story of Beowulf, it's obvious that both evil and heroism coexist. As long as the protagonist, whose name is Beowulf, and antagonist, either Grendel or his mother or the Dragon, confront to each other, evil and heroism both take place.
          Each of the eight scenes in the story annotates the concept of heroism and evil. From scene 1 to scene 3, evil is defined by Grendel's sudden attack on Hêrot while heroism is defined by Beowulf's appearance to save the Danes; from scene 4 to scene 5, Grendel's mother's attempt to avenge for her dearest son is the principle of evil in these 2 scenes while Beowulf's appearance still remains as major impact of the heroism; from scene 6 to scene 8, the perspective of evil shifts to the appearance of the Dragon who later kills the glorious kind of the Geats, Beowulf, while a new hero, Wexstan's son Wiglaf, fearlessly shows up and reinforces Beowulf to defeat the Dragon at the end of the story.
          All in all, evil in the story of Beowulf has occurred whenever an antagonist shows up and heroism has manifested itself in Beowulf by giving the credits to the heros such as Beowulf and Wiglaf. Regardless of the appearances of other innocent people such as Hrothgar and his "prime minister" Unferth, those characters are basically just parts of the background setting.