What, Exactly, Are Servants?

Servants are Heroic Spirits made into special familiars by the Holy Grail to compete under Masters in the Holy Grail war.

Unlike normal familiars, Heroic Spirits are the most powerful beings, such that they are beings beyond magecraft. Magi can perform rituals to borrow and mimic their powers, however, even summoning remains impossible. Even the Holy Grail does not have the power to summon a pure Heroic Spirit, and thus are limited to making mere copies by using information from the life of the spirit. 

Since the copies are disconnected to the main bodies of these spirits, memories forged through summonings do not get recorded by the Grail, thus, every spirit summoned for the war lacks the knowledge from their past summonings and are able to use only information stored by the Grail.

In order to sustain the summoned mimicry of these Heroic Spirits, they are given vessels that act as their temporary identity and means of existing. Heroes are given vessels that match the attributes and skills of their original classes, and a mismatch can cause a severe disparity between the fighting ability of the vessel and the actual fighting ability of the spirit. Usually, the parameters of the heroes are downplayed to match that of the master’s capacity.

Upon their designation to a vessel, heroes are given the minimum knowledge required for them to function appropriately in the specific era. This usually includes basic communication information (such as learning new languages), and knowledge on developments on their field (such as information on motorcycles and planes for Riders). However, their knowledge is not all-encompassing. 

Some concepts that are different from their time (such as traditions, ethics, technology and events) may have to be further explained to them in order to be understood. Even their knowledge of other heroes are limited-- they are not granted free information of the identity, except for those they already knew during their lifetime. 

However, those information obtained from the Throne of Heroes allow them to deduce information about other heroic spirits. Learning about other spirits’ identity allows Heroes to discern their abilities, strengths, and weaknesses as an individual hero may have known them during their lifetime. While not always the case, some Heroic Spirits conceal their names to not let this information be used against them.

Heroes can change from their spiritual body and their material body at will. While in spiritual form, they are liberated from the humanly limits of existing. The lack of a physical body makes it difficult for other spirits to detect a hero’s existence, let alone be impeded by material objects in their travels. 

However, lacking the body also prevents them from carrying objects, and the lack of humanly senses prevents them from taking in sensations other than spiritual ones. Upkeep costs of a spirit is lower when they’re in their spiritual form, however, they cannot transmit information to their masters that rely on the five senses. In order to affect a material object and engage in combat, heroes need to be properly materialized in their respective vessels.

These vessels, while strikingly similar to humans in outward appearance, hold a remarkably different composition. Vessels are considered better in physiology, and are more efficient than a human’s. As such, transplants from vessels to humans are difficult, if not outright impossible, because the human body could only hold so much before it is overwhelmed.

And while Heroes bleed and receive damage as most humans, they cannot be defeated by mere physical damage. Their true being resides on a Spiritual Core afforded to them upon materialization, directly connected to the heart and the head. It diminishes with the amount of damage the body sustains, more so in the heart and in the head, and with a more dire situation, it also increases energy expenditure. However, for a hero to be completely defeated, they must destroy the spiritual core directly, which prevents the hero from materializing.

In the beginning, only benevolent heroes were summoned by the Grail. However, its corruption allowed to the eventual summoning of darker, evil spirits to serve as Masters. More recently, upon the explosion of the Holy Grail into smaller shards, it allowed for the birth of a new type of Servant: Feral Servants, a different subtype of servants that defy the usual process of Servant creation and summoning.

Summoning heroes, first and foremost, requires the invocation of a Summoning Ritual, which requires the formulation of a runic circle. A catalyst may be used to bypass the spell incantation. There are other means of summoning a Servant, however, such methods may create abnormalities on the Servant summoned.

Catalysts are items symbolic to the Hero being summoned. These are relics that should have a direct connection to the hero, otherwise, it may take the attention of multiple heroes and end up giving the summoner a hero that has a strong affinity with them. Using a weak catalyst also gives the same effect. Catalysts that connects with only one heroic spirit, however, can successfully summon the desired spirit without regard for the magus-spirit affinity.

When summoning with a catalyst, the magus can summon strong spirits, however, they gamble the risk of an unhealthy connection as Master and Servant due to bad compatibility. Summoning without a catalyst, however, relies heavily on the good affinity of the hero to the magus rather than the actual power of the hero. 

Usage of a catalyst, however, does not fully determine the future relationship of a Master and a Servant. Those summoned with a catalyst may have a good relationship with their magus, should they relate well with each other; while those summoned without catalysts may still end up with a sour relationship due to having personalities and ideals that may be uncannily similar.

While Servants are usually sustained by the Magical Paths and energy afforded by the Holy Grail, some
Servants have to find a means to sustain themselves.

Servants without Masters or have Masters that cannot sustain their energy consumption are forced to consume energy from human souls and have to exchange bodily fluids with another individual to replenish their energy. Eating food replenishes this consumption by a small bit, while sleeping halts the energy consumption. Dematerializing weapons and maintaining their Spiritual forms also help in preserving their energy.

Since Masters serve as their anchor to the world, Servants have a compelling need to find new Masters in order to retain their existence. Without the sustenance they receive, Servants can only remain materialized for a limited amount of time, although those with Independent Action may sustain themselves longer than those who don’t.

Materialization is important not only in engaging in battle, but also in interacting with other spirits. More specifically, materialization is required to make proper contact with other Servants, and creating new contracts with Masters.

NOBLE PHANTASMS

A Heroic Spirit’s most powerful weapon comes in the form of their Noble Phantasms. These phantasms are armaments that utilizes humans’ imagination as their core, as well as objects owned by the spirit in their human lives, or concepts they embody during that time. These are manifestations of the mysteries that each hero symbolized in their legends and their facts. As Servants, their Noble Phantasms serve as their special abilities, their trump cards against other Servants.