What is ominous about the behavior of Beowulf and men during the final battle?

All of Beowulf's men desert him except Wiglaf in his final battle against the dragon. The narrator chastises them for their cowardice and so does Wiglaf in a speech. Beowulf kills the dragon but he is assisted by Wiglaf. Beowulf receives a mortal wound and orders Wiglaf to bring him treasure they had won from the dragon's tower lair. Beowulf also instructs the thane on his burial wishes which he executes very well.