Fourth Magic

The **Fourth Magic** (第四魔法, *Daiyon Mahō*?), also referred to as **Laplace's Demon** (ラプラスの悪魔, *Rapurasu no Akuma*?), is one of only five remaining True Magics.

## History

The Fourth Magic was originally achieved by an unnamed Magician. He had disappeared from history entirely although modern magi still insist that the Fourth Magic exists. The Fourth Magic remains in the dark until Kischur Zelretch Schweinorg, the Magician of the Second Magic, revealed to the magus world that the Fourth Magic indeed exists and that the unnamed Magician had passed on the Fourth Magic to Eskarne of Basque, the tenth-ranked of the Dead Apostle Ancestors, an organization Zelretch himself is a member of. Kischur, however, used all of his influence to not have them question Eskarne as she has absolutely no information that would help the magus world outside of her knowledge of the Fourth Magic. This is due to the unnamed Magician having completely erased any evidence of his encounter with Eskarne.

## Effects

The domain of the Fourth Magic is **Omniscience and Omnipotence of Atomic Structures** (全知全能原子, *Zenchizennō Genshi Kibo*?). To put it simply, The Fourth Magic gives its user unimaginable processing capabilities so that they can fully understand and comprehend the precise location and momentum of every atom in the universe and their past and future values at any given moment. The Fourth Magic also allows for the manipulation of any given atom's (or atoms') location and momentum. An example of this would be knowing the trajectory and speed at which the pieces of a shattering glass window travel (the observation half of the Fourth Magic) and tinkering with said trajectories so that the pieces do not slice a bystander's throat, thereby preventing the bystander's death (the manipulation half of the Fourth Magic).

A peculiar effect of the Fourth Magic not seen in any of the other True Magics is that it gives a telltale sign that it is being used by temporarily discoloring the user's eyes green. It is unknown why this is such, however, Kischur surmised that this was simply just a necessary procedure for the Magician of the Fourth Magic to undergo before utilizing the Fourth Magic.

**TBA**

### Vector Manipulation

An aspect of the Fourth Magic is the manipulation of vectors. Given the Fourth Magic's ability to know the location of an atom, regardless of its location in the past or future, and that movement requires a geometric object with magnitude (or length) and direction, it should come to no surprise that the Fourth Magic allows for the manipulation of Euclidean vectors. This is the main application in which the Fourth Magic is used by Eskarne's heir, Ayaka Sajyou, whom she had taught much to the disapproval of Zelretch.

As per any other use of Fourth Magic, when one utilizes the vector manipulation ability, their eyes glow green as they perform the numerous calculations needed to properly parse and control the vectors as there are multiple variables in any given vector. This ability is extremely versatile and has multiple purposes ranging from offense to defense. However, the most glaring weakness of this ability is that even a slight dip in concentration will result in an error in the calculations and nullifies the intended effect.

## References

**Ayaka Sajyou's Vector Manipulation [True Magic]**

The True Magic wielded by Ayaka Sajyou is one of only five remaining True Magics, the Fourth Magic, otherwise referred to as Laplace's Demon. She was taught the Fourth Magic from her mother and mastered its use via vector manipulation.

**The Fourth Magic [Laplace's Demon]**

Wielded by the tenth-ranked of the Dead Apostle Ancestors, the Fourth Magic, otherwise referred to as Laplace's Demon is one of only five remaining True Magics, relics of the Age of Gods.