Shin Hokuto no Ken

The events in both of these OVAs happen in a post-apocalyptic world. The main characters are both tall, muscular and very powerful men. They also try to help innocent people by killing evildoers in gory and violent ways. 

The events in both of these OVAs happen in a post-apocalyptic world. The main characters are both tall, muscular and very powerful men. They also try to help innocent people by killing evildoers in gory and violent ways. 

While the premise of these series are different they do share similar story themes of civilians becoming corrupt in their pursuit of justice; being able to justify their murderous actions for people's safety. Both anime also share similar style of music as Takanashi Yasuharu composed the soundtracks for both series. 

Both contain powerful manly characters and gritty violence. Midway through the story, the focus shifts from the main character to the supporting cast as it interprets the gradual corruption of people. Such examples include revenge and religion and a very grey look on morality. New Fist of The North Star displays the world's society fighting for ambition and survival while Golgo 13: The Professional encourages Leonard Dawson's obsession with revenge.  

Certain episodes of Fullmetal Alchemist focus on a manipulated religion and its effects on the people. New Fist of The North Star also revolves around a similar premise as the people are being deceived by fake Gods and are willing to commit murder for their religious beliefs. 

Both OVA series display a need for a courageous and pure spirit to battle tyranny. New Fist of The North Star shows the failings of religious lunatics while Captain Herlock Endless Odyssey explores fear and hysteria.  

Both titles are set in a post-apocalyptic setting after the earth was destroyed by a devastating event. The main protagonist in both anime uses martial arts to kill anyone that stands in their way. They are also both action-packed anime with lots of blood and gore. The differences between the two is that Apocalypse Zero is more over the top and has mutants for enemies while New Fist of the North Star has humans for enemies and has a better story. If you enjoy one, you should like the other as well.