The Sacred Arts are Cradle's magic system.
In the world, vital aura gathers around the elements it belongs to; for instance, stone aura gathers around stone, and water aura gathers around water. The more of an element that is present, the more aura gathers there. Slowly, and at different speed for different elements, the elements themselves, will start to gather the aura, and if left undisturbed for long enough, these veins of vital aura are refined into a higher state. Pools of water will turn into sacred pools, which are often used to refine elixirs, and Titan's Bone, which comes from stone, is almost unbreakable.
Madra is the energy running through our bodies. It is used to power techniques, and “cycling” it and using it for techniques is what we call practicing the sacred arts.
Your body is built up with a madra core in your center, usually placed just beneath your navel, and madra channels, looping from your core through your body and back. This mimics blood veins, but for madra. There are three ways to replenish and expand your madra pool. One, you can cycle it. Two, you can draw in vital aura from around you. This does have to be aura that is either pure, or of the same type as in your core. Three, you can use elixirs and pills.
As a default, a newborn baby will have pure madra. This madra is the only one that doesn't have a corresponding vital aura. To get your core to another kind of madra, you have to cycle vital aura of the chosen element(s), which will slowly turn your madra into that kind, until your body at last produces that kind by itself.
There are multiple ways to cycle madra. One can cycle to take in and process aura, one can cycle to use a technique, one can cycle to restore lost madra, or one can cycle to refine and control the madra you already have. All of this will be done at different time throughout your life, as you use your madra.
There are four kinds of techniques that you can use. Often, a technique will be a combination of multiple technique styles. As you use a technique, it will get engraved into your soul over time, which make a technique stronger and more versatile.
Strikes your opponent with madra from a distance.
Creates stable, physical manifestations or objects of madra.
Empowers your body or something you are holding. Depending on madra type and technique, the benefits will vary.
Uses madra to control vital aura to create an effect around you, for example control wind or trap your opponent within illusions.