Spirit Realm, the preparatory stage before taking the first step into the mystical world of cultivation. This is where the body becomes a whole, and the power of the cultivator's mind and soul starts to develop.
The five Main or Fundamental meridians located in the arms, legs and the forehead, make up the most basic Qi circulation infrastructure. It is this infrastructure that is expanded and improved upon in every subsequent realm thereafter.
That is why it is of extreme importance that everything must happen smoothly, and most important of all, naturally.
Until all five meridians have been opened, the Qi circulation system can never be completely activated.
This leads to significant inefficiencies in its normal operations and a several-fold increase in the expenditure of Qi when using different abilities and attacks. That's the main difference between the Spirit realm and all preceding realms.
It is a difference in both quality AND quantity.