I write a pretty well-done review..then the website told me that it was too long AND DELETED IT! (WTF anidb?), so here is the main idea:
Hokuto no Ken change the narrative world, almost everything that you see in Saint Seiya, DB, HxH, One Piece (and the rest of that kind) are ideas taken from Buroson
Manga: 10 (it has more mature content, as religion, philosophy, etc)
Anime: 9 (awful drawing, more bad quality filler)
Explanation by michkrol on Tuesday, 13.08.2013 21:07
Characters in both are nearly almighty and use ancient super-power-like arts during their fights.
The overall feel of these two series is very similar.