Magic
Although she didn't find the book she wanted, Xuan Yiran gained a lot of basic knowledge about the Sri Lanka continent here.
What she saw was that those people used strange abilities which were actually magic, a special ability produced by the friction between this world and another adjacent existence.
That adjacent yet invisible world is not the Earth she is on, but an existing or possibly non-existent element of another world. The user will use their own strong spiritual power to reach into that invisible elemental otherworld and guide the elements that exist there into this world, which is magic.
However, these people who possess magic are not called magicians but rather a race of people.
Unlike magicians, these magical races often infuse magic into their weapons as a combat enhancement tool, rather than relying on the tiny magic wands that can solve everything with just one wave.
However, there are special cases, such as healing magic, which has no killing power but is indispensable, and summoning magic, which is a special ability that can summon magical beasts. In fact, without special reasons, it is unlikely that anyone would be willing to learn or accept this ability.
It requires a powerful force, and it must be exchanged with something of equal value to oneself. The demon beast is also known as a kind of devil, and using them requires sealing a contract with an equally valuable - soul.
When the contract expires, it will be the time when the person's soul is taken away by the demon.
Taking away the soul is equivalent to death, and it's said that the remaining flesh will also be eaten by the demonic beasts. Because they don't allow their former masters to be eaten by other creatures of the same kind, which can also be seen as a last loyalty to their former master.
This is not loyalty, Xuan Yan felt it was too absurd, it's simply cruel to the end. What is no bones left, that's what it is.

