In the Fate series, Spirits are spiritual beings that appear across time and in various parallel worlds. The most common type is the Servants, or Heroic Spirits, who are powerful, well-known historical figures summoned by masters to take part in the Holy Grail Wars. Over the years, Spirits have evolved to include more than just Servants, like other prominent mythological and cultural figures as well.
Although Spirits are mostly made up of Heroic Spirits and benevolent gods, not all of them have humanity's best interests in mind. Throughout the Fate series, several Spirits known as Beasts have made it their goal to wipe out the human race, but thanks to the Heroic Spirits, they have been stopped time and time again.
Note: This article contains spoilers for Fate/Zero and Fate/Stay Night: Unlimited Blade Works as well as the rest of the Fate series.
The Fate series has several different servant classes with seven main servant classes
The main seven servant classes were first created during Fate/Zero and Fate/Stay Night. These servant classes consist of three Knight classes and four Cavalry classes. Knight classes include Saber, Lancer, and Archer, and the Cavalry classes include Caster, Rider, Berserker, and Assassin.
1) Saber
The Saber class is a group of servants who utilize swords as their main weapon. When they lived on earth, these servants typically led armies to battle and served their countries as either loyal aides to their rulers or as rulers themselves.
Saber class servants are often classified by their unwavering ability to lead armies into battle. No matter their opponent, they will stop at nothing to keep their master safe.
The best and most powerful example of a Saber class servant in the Fate series is Artoria Pendragon. She is based on the fictional King Arthur and is the servant of Kiritsugu Emiya in Fate/Zero and Shirou Emiya in Fate/stay night. Both her skills as a knight and Excalibur make Artoria Pendragon second only to Gilgamesh, the King of Heroes.
2) Lancer
Lancer class servants are incredibly versatile in the Fate series. Their spears allow for both immense range and thrust power. They also have the skills of a hunter, which allow them to adapt to all of their opponents' battle styles.
As a result, the Lancer in Fate/Zero was able to easily parry Artoria Pendragon's every time they battled. Cu Chulainn, the Lancer of Fate/Stay Night, was an even better combatant than his Fate/Zero counterpart.
Cu Chulainn was able to match and block the attacks of both Artoria Pendragon and Sasaki Kojirou, an Assassin class servant. He was also able to catch Kirei Kotomine off guard and kill him with ease. Cu Chulainn's ability to compete with the fastest and strongest Servants makes him a true Lancer.
3) Caster
In the Fate series, Caster class servants are masters of mana manipulation. They use the natural mana they and their Masters produce to cast various spells for both offense and defense. That being said, Casters tend to have much lower physical strength than the average servant, but they make up for this downgrade with their immense mana reserves and magic power.
In Fate/Grand Order - Absolute Demonic Front: Babylonia King Gilgamesh was portrayed as a Caster. He still had access to his signature Gate of Babylon, but instead of an endless supply of weapons, he would launch powerful spells capable of bringing the gods to their knees.
4) Assassin
Assassin class Servants are known for their ability to strike hard and fast. They typically stick to the shadows, attacking their enemies when they least expect it.
They are perhaps most similar to Archer class servants due to their high reaction speed and small recovery time. If they get hit by an opponent, they can get back on their feet and back into their feet almost immediately.
The most notable Assassin class Servant in the Fate series is Hassan of the Cursed Arm. He was able to split himself into multiple Heroic Spirits at the same time. This ability is quite similar to Naruto's shadow clone Jutsu as the clones are capable of transmitting their experiences to the original.
5) Rider
The Rider class is an incredibly powerful servant in the Fate series, mostly thanks to their indomitable will. Unlike all other servants, the Rider of Fate/Zero, Iskandar, never had a single moment where he felt like giving up. Even when he faced overwhelming forces alone, like his bridge fight with Gilgamesh, Iskandar never looked back.
Rider class Servants have an inherent ability to conquer both other Servants and their masters with overwhelming force. On the other hand, they have a human side that other Servants do not seem to retain after becoming Heroic Spirits. This allows them to create a close bond with their masters, making them an almost insurmountable team.
6) Berserker
Berserker class Servants are known for their immense strength and absurd behavior. They tend to attack anything and everything in their vicinity besides their masters. Even when unprovoked, they launch relentless attacks on Servants and masters alike. This was a constant theme in both Fate/Zero and Fate/Stay Night: Unlimited Bladeworks and the rest of the Fate series.
Despite their crazy nature, Berserkers are incredibly loyal to their masters. Although all Servants are, the masters of Berserkers rarely ever need to use Command Spells to have their servants do their bidding.
7) Archer
Archer class Servants are well-rounded war machines. They take and execute commands given by their masters without fail, regardless of their opponent. While this is not very true with Gilgamesh due to his arrogant and rebellious personality, Gilgamesh is anything but normal.
These Servants also have an abnormally large range of attacks. Both Gilgamesh in Fate/Zero and EMIYA in Fate/Stay Night: Unlimited Blade Works can hit enemies from miles away with perfect precision. This makes it very easy for them to launch ambushes on unsuspecting masters and Servants.
Special servant classes
1) Grand Servant
Grand Servants are a special servant class derived from the main seven listed above. These Servants are typically the most powerful and highest ranked Servant of each class. Although they are meant to be all equal in strength and power, Artoria Pendragon will be the most powerful of them all as long as she has Avalon.
With Avalon, she will be completely immune to all attacks from any opponent. She will be the most powerful being in the entire series, capable of taking down Servants, Gods, Beasts, and any other powerful beings in the Fate series. The time she got closest to obtaining Avalon and being the best candidate for Grand Saber was during Fate/Zero.
2) Beast
Beast class Spirits are the antithesis of Grand Servants. They are represented as natural disasters with the sole purpose of destroying the world and eliminating humanity. In fact, the whole reason Grand Servants were created and summoned in the first place was to take down Beast class spirits and save humanity from extinction.
Beast class Spirits typically embody the negative side of humanity, essentially feeding off all the bad actions made by humans. Tiamat in Fate/Grand Order - Absolute Demonic Front: Babylonia is one of the most powerful Beasts in the series.
3) Ruler
Not many Ruler class Servants exist in the Fate series, the most notable being Jeanne d'Arc and Amakusa Shirou Tokisada, another interpretation of Shirou Emiya's future self.
Ruler class Servants are known as non-standard Servants, meaning they do not fit into the main seven Servant classes listed above. Rulers specifically were summoned to preside and watch over the Holy Grail Wars to make sure neither the masters nor Servant break the rules laid out. In fact, Ruler class Servants are given Command Spells, allowing them to force Servants into acting within the rules of the Grail.
4) Shielder
Shielder class Servants are a very new type of Heroic Spirit. Currently, Mash Kyrielight and Galahad are the two main Shielder class Servants. Despite this, not much is known about this non-standard Servant class in the Fate series.
However, based on observations made of the show, Shielder class Servants tend to have the greatest defensive abilities of any other servant. They are capable of defending against some of the most powerful attacks from other Servants, including Noble Phantasms.
Final thoughts
The Fate series is filled with an intricate plot that has caught the hearts and minds of various anime fans. The concept of Heroic Spirits and other spiritual beings taking root in real-life history and cultural mythology was very unique when Fate/Zero first aired.
Although the Fate series initially began with seven primary Servant classes, it grew to include all types of possible warriors and powerful beings. This gives the Fate series a uniqueness no other anime has.