[If you got here, I congratulate you. It's not easy to be chosen by a powerful entity. But you did it. I'm proud of you. But the road will not always be easy from now on. Maybe that's why you are reading my manual. Well played.]
1. The four elements - water, earth, fire and air - are the basic elements in the constitution of the Earth. They are essential to human life.
2. The elements of nature can be associated with:
Earth → Solid
Water → Liquid
Air → Gaseous
Fire → Plasma2.1. Earth: the earth is us; terrestrial beings, people, animals, plants. Without us and the animals, the land would be empty and meaningless.
2.2. Water: water occupies 70% of the Earth's surface and it is essential for life, which, without it, there is no water.
2.3. Air: the air is what we breathe, what we smell, good or bad, and what we pollute. Without air, there would be no life on Earth, not even on the sea.
2.4. Fire: the fire is us, because it's a mixture of substances. Fire is known for its energy; we are composed of energy. Furthermore, it can also be seen as the sun, which warms us. And without sun, there is no life.
3. There are four guards, each corresponding to an element.
3.1. Guardian: holds a certain power, which can only be used for the benefit of the community. At the end of its mission, they can rest in peace for eternity, as an angel or demon. Therefore, they lose the power of their element, which will then be assigned to a new guardian of the following generation.
3.2. Each guardian should use the power of their element to overcome evil with the help of a high-strength gun which will be assigned to them by the institution. Besides it, fighting hand-to-body becomes essential to achieve success. They can also count on numerous technological objects to facilitate their mission, such as a teleportation mechanism and intercommunication between worlds (Earth and magic).
4. "Sleeping pill": when in an extreme situation, a guardian is about to lose its element to the enemy, ot will be begin to him the option of committing suicide, eating the so-called sleeping pill. The element will leave their body and will take over the body of another human predisposed to the position of guardian.
[I hope it helped you. Now that you become a guardian, you need to practice, to train, to get strong, to believe. And remember: you don't choose the element. The element chooses you!]