User Recommendations for Darker than Black

Strong main male characters in Hei and Kiritsugu, both distant but powerful. 'Contractors' in Darker Than Black are the main source of supernatural power, whereas in Fate/Zero they come from a third party 'Servants'. Both have plots you can sink your teeth into and have a very similar feel to them, though differing plot.

Both Anime have relatively dark plots and multiple twists Hei has a very similar personality to Fate Zero's Emiya Kiritsugu Both are not afraid to kill off characters Based around a supernatural phenomena: Darker than Black- Hell's Gate Fate Zero- Holy Grail

Both the Hei and Kiritsugu are much alike Both share dark atmosphere Both animes have great batles and are very sad. Same feelings.