Magical Energy

Prana (魔力) is the power source used to actualize the mysteries of Magecraft.

Mechanisms
Prana cannot exist independently or do anything by itself, so is always bound to some sort of recipient. For that reason, the magi use it mostly by imbedding it into an object or as a catalyst to initiate nature interference Magecraft. The only exceptions to the said rule are the Holy Grail of the Einzbern's and demons, who recreate miracles by just releasing energy.

Prana is divided into two types:

Mana
Mana (マナ) is the life force of the planet and exists in the atmosphere. It is produced by the world itself. While mana is usually found in great quantities, it takes a long time to replenish once it is used up. It is the primary source of energy for Nature Spirits.

Od
Od (オド) is the energy found within living organisms. Once depleted, the Magic Circuits that are stored in the soul will begin to replenish it. Od is produced as long as one lives, but the amount a person can store varies from individual to individual. It's name is more than likely derived from "", which is a hypothetical life force.



The difference between mana and od is their abundance. Mana can be found almost anywhere and in great quantities, thus it is called the Greater Source by the magi. As od is the energy inside humans, it is much smaller in amount and is called the Lesser Source. Strictly speaking, mana and od are energy in it's raw state, while prana is the name given to the energy once it is converted by the Magic Circuits. Mana can be taken in accordingly with the capacities of the Magic Circuits, but the actual conversion process will take time.

Regarding nature interference Magecraft mentioned before, at least for those of large-scale, activation requires the use of mana regardless of the amount of od that the magus has. In fact, it is common practice among the magi to start up their spells with od and then keep them running with mana. Only small-scale spells that do not interact with the environment directly are performed entirely with od, an example of which would be Reinforcement.

Prana itself does not have any elemental attribute. However, once imbedded into an object that does have said attribute (such as jewels) or that is under the influence of nature spirits, it will attune itself to the elements in question until the moment that is released.

The magic energy itself is held only inside the body fundamentally and if released in the outer world, it will return to life force and be scattered into the Greater Source. This has also been expressed as "evaporation". Magic power is prone to merge with the fluids (such as blood or semen) of the magus, and these fluids are good at holding in magic energy for some time even after leaving the body. Because of this, by drinking a magus' blood, one can replenish one's magic power. Magus with monetary problems have also been said to sell their body fluids, in which magic energy has been merged, to the Association.

Od levels by character

 * Average matured magus: 25 units of prana (Fate).
 * Ciel: 100 times the amount of a magus (2500?). Exact number is uncertain due to differences in the standards of the sources in question (Tsukihime vs Fate), but she is definitely Servant-level in terms of capacity.
 * Emiya Shirou: 20~30 units of prana.
 * Matou Sakura: Normally, she should have about the same amount as Rin, but the Worms in her body are constantly consuming her energy. When connected to the Holy Grail and Angra Mainyu, the energy inside her body is equivalent to 1,000,000,000,000 units of prana, already on the level of a Counter Guardian.
 * Rider’s Pegasus: 100 times the amount of a magus. About the same as Ciel (approx. 2500).
 * Saber (with Shirou as Master): 1200~1300 units of prana.
 * Tohsaka Rin: 20 times the amount of an average matured magus, so about 500 units of prana.

Random Facts

 * Aozaki Aoko is capable of absurd feats of Magecraft using just her od. An approximate comparison would be of a car traveling 1,000 kilometers with only one liter of gasoline.
 * Caster’s cost for:
 * Single bolt of light: 70~200 units of prana
 * Rain of light: 700~2000 units of prana
 * Emiya Shirou’s cost for:
 * Reinforcement: 2 units of prana
 * Tracing: 5 units of prana
 * In ancient Egypt there was a practice of sewing one's eyelids together to prevent prana from escaping the body
 * Saber’s consumption (with Shirou as Master):
 * Battle with no damage: 10 units of prana
 * Amount regained per day: 8 units of prana
 * Amount needed to maintain her body per day: 6 units of prana
 * Amount spent fighting in the first day: 250 units of prana