【'Mana Depletion Syndrome' Series】

A vast continent of Arsgald, where history has been woven through developed swords and magic, along with a touch of medicine and science.
There, for several years now, a certain disease has been spreading. Those afflicted gradually lose their magical power and become unable to move their bodies. Furthermore, as the disease progresses, it slightly activates a person's 'lust' and 'instincts.'

The name of that disease was called 'Mana Depletion Syndrome.'

The method of preventing 'Mana Depletion Syndrome' is unknown.

The more magical power one has, the more severe the condition becomes, and there is only one treatment.
The treatment for 'Mana Depletion Syndrome' is to regularly intake magical power. There are three methods.
One: Intake through food. The amount is small.
Two: Intake from magic stones. Side effects may occur. The amount that can be absorbed is also not large.
Three: Having it transferred from another person. However, it is difficult to adjust, and there is a risk that the person who transfers it may lose their magical power. Mucous membrane contact is required.

Along with the spread of 'Mana Depletion Syndrome,' wars being waged across the continent came to an end one after another, or their scale shrank. At the same time, a certain kind of damage was increasing.

That is 'Monster Damage.'

'Mana Depletion Syndrome' does not infect monsters. Therefore, monster damage was spreading across the continent of Arsgald.

The place on the Arsgald continent that suffered the most from 'Mana Depletion Syndrome' was the Magic Kingdom in the northeast of the continent, commonly known as the 'Magic Tower.'
The 'Magic Tower' is the country where magic has developed the most on the continent. There is no king, and the country was governed by the 'Five Great Mages.'
However, the 'Five Great Mages' who rule the 'Magic Tower' have contracted 'Mana Depletion Syndrome.'