Psyche magic is the way to interact with the Psyche plane through Psyche Nodes, mostly used to alternate someone's mind the way the mage wants it to be or to protect their own mind against other mages.
Psyche Node is the connection to the Psyche plane. The connection allows different kinds of interactions with the plane if the performer has a capable psyche for it with other Psyche Nodes, and therefore with their owners.
In general it requires a conscious effort, therefore "draining" and overloading performer's brain. A psyche mage is called "psycher".
The plane allows the ones with the connections to read and write the dimension data, including the Psyche Nodes of their opponents. Of course most performers do not see it as such, as their brain translates the interactions into a simpler forms. Most of the magic can be described as sequence of reads and writes, where writing is always harder than reading.
Catalyst
A Mana Catalyst that allows the psyche plane interactions through a Psyche Node it is connected to. Mostly can be seen used for the psyche magic
Brain
By some reasion all the Deus-created dimensions contain almost exclusively only living creatures with their brain as a psyche catalyst. The more developed intellectually they are the better connection it allows.
Power
The catalyst powers can greatly vary depending on many factors.
If catalyst is biological, then potential of it mostly will be defined by the body of the owner. (brain capabilities, race etc)
Catalyst Destruction
When the catalyst is destroyed the Psyche Node stays in the plane despite wishes of the owner and their physical body's status in inactive status, so consciousness does not work and just "freezes".
See also
Usages
The psyche magic allows for many things, all related to mind of living or not very creatures.
Protection
The most obvious and the most common usage of psyche magic is to protect the mage against other mages.
It requires concentration and effort from the mage to resist the effects of the psyche magic to keep their own psyche as untouched as possible, cutting any psyche-connections as quick as possible.
Telepathy
The telepathy allows the caster to read mind of target or send some thoughts to them. It is done through interaction with the part of their psyche that is responsible for storage of the most recent information, cache if you will. The "cache" part is severely protected, so the most basic usage would be both sides agreeing to connect their minds to "hear" each other thoughts allowing them to quietly communicate with each other.
Reading mind of resisting target is way harder than this and requires high skill and capacity of the psycher performing it. Unaware target despite despite not agreeing to give their thoughts is an easier target as their psyche defenses are lower so it'd be easier to read their mind.
Illusion
Forcing false senses to target(s) mind is the Illusion. The caster sends additional sense information to psyche of the target making them see, hear, smell etc something that does not exist making them believe in it.
The more senses it forces on target, the more targets there are the harder to cast this kind of magic is.
Feelings Imposition
Other
The psyche magic can have and has way more usages that are not described here, some psychers can make up their own and not share it anyhow leaving it only to themselves to get some advantage on the battle field or in their everyday life.