Synesthesia.
The phenomenon in which a person's sense comes through as another. For example, when you can 'taste' a sound, 'smell' a word, 'hear' a picture, and 'see' a scent.
A magical illusory field, one that was built with Mana, was something that used this phenomenon to the fullest.
To make something look convincing and real, one couldn't simply use their Mana to create a space. To deceive their victims, illusory fields must mess with their senses and create synesthesia from within their brains.
Especially when their victims were masters who could sense the littlest difference in the air and dodged an attack from it.
To truly deceive, the illusory field played with the senses, triggering synesthetic experiences within the minds of its targets.
It was an art of deception, weaving together sight and taste, sound and smell, forming a tapestry of sensations that captivated and deceived in equal measure.
