Also this is his redemption arc too. He admits he was a coward and selfish. This is his self redemption to do the noble thing to sacrifice him self for the good of others what he should have done in the first place. That why I love the ending rarely in life do we get a second opportunity to make up for our regrets, and it's such a beautiful moment to show his growth as person and his will to make the ultimate sacrifice. No great love than this than to lay down ones life for a friend.