This is basically a Shounen harem version of Zero, where instead of focusing on many characters, the focus here is all on one. The main character gets surrounded by females to a point where it just gets ridiculous and it's hard to take seriously. His relationship with his "servant" also is really hard to take seriously, especially if you consider that his servant was originally male. Nevermind why the hell it's a female here, I have no idea why after two shows featuring him/her.
For a story about a War between epic heroes, they are really underused which is a crying shame. They have a finishing move called a Noble Phantasm but we barely get to see them and half of them don't even use theirs.
While I kept watching to see what would happen next in the second half of the series which had great pacing, I was extremely let down by the last few episodes and the ending, even getting pissed off. The only reason I kept at it is because of having seen Fate Zero first, so I would recommend staying away from this if you haven't seen or didn't like Fate Zero. That being said, I am checking out the other Fate adaptations soon, just because Zero was so enjoyable.
