The Sealing System:
Imagine there is a cup made of clay and filled with water. The water is spiritual energy and the clay is the container.
There are a few rules governed by the magic system.
1. The amount of clay increases slowly with age.
2. The water inside the cup can only be replenished with rain from the sky
3. The amount of clay and rain is temporarily increased at birth and at puberty during the awakening.
4. Applying a seal is like taking clay from the cup and forming a smaller cup. However, in order to use the seal, water must be poured into it from the main cup such that the smaller one overflows.
5. All smaller cups must be full of water to be used, and overflowing to be fully realized.
6. Only the main cup can be filled by rainwater.
Using these rules, everything regarding human magic is set in place.
Wu Bao' Dragon Sealing Talisman is special because it can steal the clay of others and pour it's own energy into those seals to fill them up. The act leaves it empty, which is why it must be refilled by the energy in Wu Bao's main cup.
It is bad to apply a seal that is too strong. It would be like taking all the clay from the main cup to create the smaller cup. Since smaller cups can't fill themselves with rainwater, the resulting cup might be too empty to be used. The best seal application let's the water slightly overflow.
One thing that sometimes happens is that seals can be broken. This can be because of a seal breaker, or the amount of water washes them away. There is a small risk during an 18 year old's awakening for them to accidentally break all their previous seals. Because of the third law, clay and rain is temporarily increased. After the awakening is over, the excess rain and clay tumbles away. Large amounts of post-awakening drainage can break old seals. This is why the characters sometimes express concern.