The gods and the fear

There were once a universe, there everything was calm, and this universe was ruled by the four gods,
They together made the universe and together they ruled it.

Thoose 4 was:
The red Bird of south, vermilion, Symbol of fire.
The east dragon azure, symbol of wood
The black tortoise of north, symbol of water
The white Tiger of west, symbol of metal

But there were also another god, the yellow dragon, the one who has the symbol of earth.

This earth dragon was selfish and were in prophetsy that one day, it would try to destroy everything.

The 4 gods knew about this and had to do something, they captured him, and sealed him away, and only if the 4 gods together agree, they would release him again.
In the time, they 4 gods choosed their own pupil, they teached the pupil how to use their masters element, but even if they learned the element, they wasn't even close to their masters powers. But still, they let them role a planet, the planet we call earth.
The gods was pleased, the could rest and let their pupils be on charge, so the gods flew to a difrrent dimension, there everthing was quiet and it was in peace.
But before they flew away, the gods told the pupils, in time, they had to release the earth dragon, and when that time comes, and if they need help, they have to call for their masters.

Meanwhile, the pupils had now the responsibility of taking care of the planet called earth, they created life, humans, animals, trees, all kinds of stuff.

It had passed 2 centuries and the gods 4 gods had started to feel weaker, they knew why, it was because they needed the earth dragon.
When they had sealed him, the balance between all elements was interupted, and they knew what they had to sooner or later, they had to release the now angry and dangerous dragon.
It was now up to the pupils to stop The earth dragon.