Incarnum
Incarnum is technically the manipulation of the soul, spirit, essence, or any other synonym. Whatever they are manifesting it has been studied to be of direct relation to their conscious being and many tests for life, especially alien, utilize incarnum as a measuring scale to quantify it. Thanks to incarnum we can be certain when someone is dead or not as death is medically defined as the moment the incarnum essence leaves the body and disperses. Though to this day no one knows where that essence goes after death. Most incarnum practitioners tend to manifest and control only their own soul but some have manipulated others instead.
One of its primary benefits, and dangers, is that since it is the users own soul it is impossible to disarm them of it. Incarnum is immune to antimagic fields and undetectable as all people have a soul whether they can weaponize it or not. Many undercover agents learn basic incarnum as a last ditch plan and almost all legal systems have special maximum security prisons to contain incarnum wielders if necessary.
In the practice of incarnum there are nodes along the body known as Chakra. In all humanoids there are the right and left arms and legs (including hands and feet), head, heart, and soul chakras. It is possible to manifest incarnum essence, known as soulmelds, through each of these chakra for varying effects though incarnum is limited in that you can only use one thing at a time with any given chakra and preparation takes a lot more time and effort then other kinds of magic.
In its most basic form incarnum is a well respected field of magic and often considered noble for its use of ones own spirit to accomplish effects. Though sometimes people start to use the darker arts of incarnum, a ranging scale of ethical gray murk that ends in the dark art of necrocarnum. It is possible to cause very serious effects on other peoples souls through advanced incarnum techniques. It has been proven possible to alter the consciousness of other beings in dramatic and permanent fashion which is most visible in changes to their outward personality. It is also possible to transfer souls from one body to another and the most abhored form of any magic is necrocarnum's ability to take souls from others and weaponize them for yourself.
In the gray territory, some have managed to rewrite the personality of criminals to better fit them into society using incarnum techniques. Some areas have opted to use this power of incarnum as a way to forcefully and quickly rehabilitate criminals or addicts. Another example is that of saving the incarnum soul of the dying and transferring them to new bodies to continue on. While it is frowned on as unnatural it often leaves ethically difficult questions when an incarnum master saves the soul of a child to put into another body so it may continue to live.
The darkest art of the field is necrocarnum. The ability to take the souls of the dying and warp them to your own will. Reanimation, lichdom, and the power to wield multiple souls for making soulmelds are all tools from the necrocarnum spellbook. While the name dates back to the age of necromancers and dracoliches, necrocarnum is technically defined as the practice of using the souls of others whether for personal gain or not. Culturally it is widely thought of as specifically using the souls of others for one's own power, but body transferrence is technically also necrocarnum even if in a grayer territory.
Incarnum users are referred to by the title "incarnates" or "necrocarnates" if they practice necrocarnum.