When he sacrifices himself for his people. This part occurs towards the end when the news of a dragon reaches him. This is also an example of caring as he is fighting for his people.
He demonstrates bravery and strength in the first fight with Grendel. He has grendel in a position where he was able to rip off his arm.
One of the main characteristics of a hero is sacrifice and benevolence. In the film Star Wars IV, Luke takes a sacrifice by risking his life trying to save Princess Leia and destroying the Death Star.
He shows benevolence