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Dark Magic (風魔法,Yamimahō?) is one of the attributes of elemental magic that exist in the In Another World With My Smartphone series. This type of magic is exclusive to mages with the Dark (風属性,Yamizokusei?) affinity.
The main use for Dark Magic is for summoning beasts in order to form contracts with them. As such, once a beast is summoned, the summoner would have to perform a certain task chosen by the summoned beast. If the summoner is unable to fulfill the task, then the contract is considered null and void, and the summoner will not be able to summon the same beast again. In Yumina's case, her task to form a contract with a silver wolf was to feed it until it was full.
The strength of the summoned beast may also reflect on the difficulty level of the task the beast might ask of the summoner to form a contract. And there doesn't seem to a limit on how many of the same summoned beast one can call forth. The wizard who attacked Sue's carriage was able to continuously summon a horde of Lizardmen, while Touya was able to summon a virtual army of beasts.
Despite being called Dark Magic, there is nothing inherently evil about this type of magic other then how one uses his/her summoned beast.
A mage needs to have affinity toward the Dark attribute before they can use dark magic. To test one's aptitude with certain attribute, a magic stone can be used. The magic stone amplifies and releases the user's magic power into the certain element that the respective stone represents. The magic stone for the Dark attribute is violet colored. If a person chants the element summoning spell while holding a magic stone, and the magic stone reacts, then the person has an aptitude for that attribute.
The users summons a cloud of darkness will form around the stone for testing their dark attribute affinity.
Before one can cast a magic spell, the user must have aptitude toward the element and chant the spell incantation correctly.Like most of the elemental magic spells, the user needs to chant the magic spell in order to activate the magic (except for null magic). In addition, the user needs to understand the magic spell effect or form before they can activate the magic properly. The spell incantation is compromised with three sentences which latter part is written in katakana for English words, which is language is alien for anyone at this world (Aside from Touya) .
The summoning in the world of In Another World With My Smartphone works based on contracts.
For make a contract the user need to do the following steps:
Magic Circle: in order for summon a being the user need to draw a magic circle and infuse his magical energy, this circle other than summon the being for make a contract work as barrier that prevent the summoned being from assault the summoner or go rampaging in the area
Pact: the summoner will talk with the summoned being with the latter that will say what want for make the contract (example, a wolf will ask to be filled of food or a demon will ask human sacrifices), if the summoner fulfill the request it will be possible proceed to the next step but if the summoner fail then the summoned being will retire and will never respond to another "call"
Name: if the request is fulfilled the summoner will give to the summoned beast a name and this will conclude the contract
Until now the summoning magic seems connected only to the darkness attribute but this fact don't prevent the chance of summoning divine beasts or holy beings.
Aside from the above steps, the summoner needs to have enough magical energy to sustain the presence of the summoned being, or otherwise it will disappear; The more powerful is the being, more magical energy will be required to sustain it.
A summoned being can be removed from the field if the summoner dies or is in a state that can't sustain the summoned being.
It is also notable that those summoning spells were used to summon the Divine beasts, but those can be found here
Because Light Magic is used to heal people it makes sense that Dark Magic (which is regarded as the inverse of the former) is used for the opposite effect, drawing out damage continuously rather than by direct attacks. Spells of this kind are referred to as Curses. As those spells have long been lost to time, the only people who can use them are people with affinities for all seven attributes.