Nicholas D. Wolfwood
Is one of the main characters in the superb anime series "Trigun".
He is an ace gunman, a priest, and carries a large gun disguised as a cross.
He uses revenge as a way of life, until he meets the main character of the series, Vash The Stampede, and understands, a moment before the end, why he was wrong all his life.
Watch the series, and understand why I find him the most interesting character in it.