The Holy Grail War. A battle in which seven masters are chosen to command seven servants. The masters are mages of various degrees of skill. The servants are iconic heroes from the past, present, or even the future. Once every master is chosen, and ever master makes a pact with a servant, the war begins. In order to win the war, and the Holy Grail, capable of granting any wish you desire, you must eliminate all of the other servants. Of course, a quick way way is to eliminate the master. If a master is defeated, nothing is holding the heroic spirit to this world, so they will disappear from the war.
Fate / Zero takes place before all of the other timelines, ten years before them in fact. It features Kiritsugu Emiya, the “father” to Shiro. We get to see what the war was really like, and the tactics that Emiya employed in order to eliminate the other masters. We know, from the timelines ten years in the future, that he “wins” the Holy Grail, but decides to reject it. Furthermore, he uses two command seals to have his servant, Saber, destroy the grail. We all know what follows, The Great Fire, in which Emiya finds young Shiroe.
So, we know how it ends. What's so special about this show? Well, the show itself is put together quite nicely. We get to see and interact with many different characters through the war. It's this aspect that lets us get different perspectives on the war, and we also learn what the different masters and servants are wanting out of the war. I like the way the show does not focus on the main characters, it's more like all of the masters and servants are main characters, which is nice. We get to know each of them and, extremely, find ourselves rooting for at least two or three of them. I found myself rooting for lancer, saber, and rider.
Just how we get to see the different characters, we get to see how each and every one of them responds to certain situations. We are able to see the varying degrees of action based on the different character's personalities. For instance, Saber's reaction to almost every situation is to either try to save someone who is innocent, and / or punish those that she feels have done wrong. Whereas we have caster and his master, simply do not give a hoot about the war and just go on a killing spree.
Most importantly, we get a lot of back story on Emiya, and why he is the way that he is. This was probably my favorite part of the story since I was expecting him to be completely different. I went a little returns with how I watched the shows, watching Unlimited Bladeworks first then watching Zero. It was nice to be able to see the man that Shiro idolized, and how he became who he was. Not to mention the crazy stuff that he had to do in order to save the majority. Lastly, we got to see the heartbreaking reason for his destruction of the grail.
All in all, this is a very beautiful series. The animation is very well done and the story will certainly suck you in. From this point in the series, it splits up into different timelines, so it's nice to get a good starting point. I would recommend watching this show not only for the characters, but the beauty of the animation. It is certainly very well done.