Fate/stay night and the massive franchise it has spawned is nothing short of astounding. The world is intriguing and the characters compelling. While some may contend the original visual novel, being the original source material, is the of the overarching saga. Yes, Emiya Shirou’s story is a classic and he’s an even more interesting and screwed up character than Kiritsugu will ever be. It’s also difficult to say that one route in the visual novel is better than the other; all of the routes contain pertinent information other routes leave out, because they are meant to be played in a specific order. That being said, Heaven’s Feel is the best route in the game and naturally feels like the successor to its prequel, Fate/Zero.
Fate/Zero doesn’t have any heroic battles. There are no heroes or villains, with the exception of one Master who is a brutal serial killer. It’s an in-depth character study of a bunch of ****cked up individuals who are so broken beyond repair that their only hope left is to cling to a “Holy Grail” which will fulfill any desire. While Kiritsugu’s wish is the noblest of all, he’s also the most twisted character aside from Kotomine Kirei, who doesn’t “find” himself until the end of the series. Archer/Gilgamesh is antagonistic, but his final confrontation with Rider shows that he’s not really any more horrible than any of the other Servants or Masters, at least in Fate/Zero.
There’s also a lot more character development in Fate/Zero in comparison to Fate/stay night. Kiritsugu realizes the mistake of his ideals through the grail while Kotomine Kirei finds his salvation in its answer. Kotomine also has that pivotal moment where he commits the ultimate betrayal, cementing his path towards years of villainy.
The only words shared between Kiritsugu and Saber directly are incredibly powerful, and was done on purpose.
Kiritsugu: “Honor and glory…theres’ no point in speaking to a killer who takes pride in such things.
Saber: “You would insult chivalry to my face, fiend!?”
Kiritsugu: “Knights cannot save the world. They call certain methods of fighting good and others evil, acting as if there were some nobility to the battlefield. Such illusions, perpetrated by heroes throughout history, have led countless young men to their bloody deaths, all for the sake of this valor and glory.”
Saber: “They are not illusions! Even the taking of life, as a human act, must have laws and ideals. Otherwise, every war would bring hell to this world! “
Kiritsugu: “And there you go. You heard her, Iri. Our Heroic Spirit here thinks the battlefield is something better than hell. What a joke. It’s hell itself. There’s no hope on the battlefield. It has nothing but unspeakable dispair. Just a crime we call victory, paid for by the pain of the defeated.
Yet humanity has never recognized this truth. And the reason for that is, in every era, a dazzling hero has blinded people with their legends and prevented them from seeing the evil of bloodshed. The true nature of humanity has not advanced a step beyond the Stone Age.”
Iri: “Then Kiritsugu, is your hatred for Heroic Spirits the reason why you force Saber to endure such humiliation?”
Kiritsugu: “Of course not. I don’t allow private feelings to interfere. I will win the Holy Grail and save the world. I am simply waging that battle using the most appropriate methods at my disposal.
Righteousness cannot save the world. I care nothing for it.
Saber: “Kiritsugu, do you understand? If you do evil out of a hatred for evil, that rage and hate will merely birth new conflict. Emiya Kiritsugu. I don’t know what betrayed you and caused you to fall into such despair in the past.
But your rage and sorrow are found only in those who once sought justice. Kiritsugu. In youth, deep down, you must’ve wanted to become a hero. You believed in a hero to save the world. You desired it more than anyone. Am I wrong?”
Kiritsugu:“I will end this ceaseless cycle. The Grail will make that possible. I’ll make sure the blood I spill in Fuyuki is the last blood humanity will ever shed. Even if that means staining my hands with every evil in the world, I don’t care. If it will save the world, I’ll do it gladly.”
Iri is also a fantastic addition to the universe as Illya’s mother and does show some character progression as the series goes on, experiencing the world for the first time and becoming her own person. Her fate though, like in typical Fate fashion, is tragic.
The servants are more interesting, the side characters are more interesting (Shinji, Taiga, and Issei simply aren’t interesting), the dynamic between Emiya Kiritsugu and Kotomine Kirei is more intriguing than any other character dynamic in the Fate saga (possibly all of anime), and the ultimate confrontation between Kiritsugu and Kotomine is one of the greatest battles in the history of anime. Fate/Zero epitomizes everything the Fate universe stands for, even if it wasn’t the original.