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It was thought of as a myth and a legend, thus considered impossible and does not exist in any records except in an old story, of which the authenticity cannot be confirmed nor disproved.
This Magic was used by Miya on Tatsuya to forcibly alter the area of his consciousness that creates strong emotions (the limbic system) in order to convert it into an Artificial Magic Calculation Area, creating an artificial Magician. This experiment caused Tatsuya to lose all strong desires.
Mental Design Interference had the side effect of weakening Miya, when she did not completely remove Tatsuya's emotions. When Maya discussed this with Tatsuya, she informed that removing all of Tatsuya's emotions would have been easier and not cause any strain or side-effects but instead she left the brotherly love he feels for his sister.