A soldier whose family was killed in front of him, who killed everyone responsible, and who then had to find out that he had been told the wrong reason.
Frank Castle is the argument these series keep having with themselves. In Daredevil he exists so that Matt Murdock has to defend a line he cannot fully justify. Then he gets his own series, and it turns out to be a conspiracy thriller about the war he fought rather than a revenge story about the family he lost.
Jon Bernthal plays him without any coolness at all, which is the only honest way to play him. The best scenes are the ones with other veterans, where the show stops being about violence and starts being about what happens to people who come back.