Answer and Explanation:
In the lines shown in the question above, we can see that Grendel is characterized as courageous and fair. That's because it shows that he is ready to face Grendel, with courage and bravery, being able to avenge the population that suffered for the acts of this monster. Beowulf is willing to promote justice, making Grendel pay for his vile acts. This can be seen, especially in the lines "alone now with GrendelI shall manage the matter, with the monster of evil, The giant, decide it."