When you are born in Karnosea, your Anima (or soul) is typically bound and born, by the Goddess Ilena, within the Echo (a reflection of Karnosea). Typically your anima lives its own life within the Echo, completely separate from your own life in Karnosea.
Your Anima takes on a form of an animal one might find in Karnosea, and is typically a reflection of one’s Id, the part of the mind in which innate instinctive impulses and primary processes are manifest; or in other words, your instinctual self.
Since you and your Anima are innately linked through the veil between the Echo and Karnosea via a metaphysical thread, if one should die, then the other will too; typically in the form of natural causes such as a heart attack. Anima do not, however, hunt one another. They do not need any sustenance to live aside from the energy shared with them via their tether. If a human were to order or coerce its Anima to hunt another human’s Anima in order to murder the human, the other Anima in the Echo would attempt to stop the murderous Anima by force before it could be successful. You and your Anima rely on each other for power, as the strength and willpower of your physical self will empower that of your Anima, and the power of your Anima will in turn allow you to live longer by surviving and sharing its magic to you via the tether.
Your affinity with your Anima grows as long as you train magical prowess and meditate in order to establish a stronger tether to your Anima, even allowing you to telepathically communicate with each other. Most who have strong affinity establish unwavering personal bonds of kinship with their Anima. Since your Anima is your Id, your instinct, the stronger your bond; the better your instincts. This means that your Anima can help you survive, from particularly dangerous situations or even to closing better business deals, by trusting in your instinct.
When a human has reached adulthood and has also developed their attunement with their Anima to a degree where they can freely speak to their Anima via telepathy, they may choose to undergo a special summoning ritual, headed by the Church of Anima. Under the grace of a Bishop of the Church, they are able to grasp the tether that binds them to their Anima and guide their Anima to them in Karnosea from the Echo. This will not merge the two of them, but allow them to co-exist together in Karnosea indefinitely.
As the Anima is considered one’s soul it is frowned upon to touch another’s Anima without express consent by the Anima themselves. Their Anima has its own underlying personality, although it is still mostly derived from the human’s Id. Anima will still resemble the animal instinct of the human it is tethered to, and can still share its magical powers with it’s human; albeit now the magical power is strengthened due to the near proximity of the Human and Anima. The Anima is also considered much safer in the MP than the Echo, since the two can look after each other. The Anima can also be used as a conduit for spellcasting, and they can still telepathically communicate. The Anima is also capable of speaking any language the Human knows.
Laust, the demibeast people, on the other hand, are often considered souless abominations by many humans, and even most members of the Church of Anima. Laust do not have a metaphysical tether to the Echo, nor do they have an Anima or the ability to summon a Anima Familiar. They believe that they were spared, long ago, when the human sorcerer betrayed the Goddesses; therefore their souls still reside within their own bodies. Laust are innately capable of magic, without any real need for any training. They also typically have stronger magical abilities than humans. However, as most were killed or enslaved by Humans many centuries ago due to this very reason, as Humans feared their power, many Laust no longer know how to access their magic unless trained by another Laust or accessing instinctually as a means of self-preservation. Laust who have developed powerful magical affinity often have odd colored fur or fur patterns, or both, that manifest on the beast-like parts of their bodies.