Deceptive
Deceptive magic is believed to be the most dangerous of the legal magics, and many who believe strongly in the light magics are trying hard daily to turn it into a banned magic. This magic revolves around all things cognitive, though it's primary use is for warping the minds of targets to cause discomfort and disorientation, and in some worse cases, severe long term damage.
Being most effective against individuals who have a traumatic history or a mental disfigurement, this magic can cause even the most emotionally strong of characters to fluctuate in emotion and delusion.
It's a hard magic to master, and has a surprisingly small amount of common uses:
Heavy illusion
Physical warping (The physical warping of a surface of surrounding radius without actually changing its properties, is usually an optical effect on a single target.)
Fear and Delusion casting
Though it can also be used against those with:
Severe traumatic history
Individuals who suffer nightmare, Insomnia or on the reverse, Hypersomnia and Narcolepsy
People with mental malformations, be it minor or extreme
Amnesiacs
Any magic which is considered a mentally warping magic by any definition of the word can be categorised as deceptive.