Under Casia's explanation, Yang Ling slowly understood a few secrets rarely known to others.
To an average person, sage-level warriors and sage-level Spellcasters were already experts that stood at the peak. However, in actuality, there were the Domain Experts above the sage level fighters, and Divine-level Experts above the Domain Experts.
Sage-level Experts all chased after magnificent Battle Energy or Magical Energy, but after advancing to the level of Domain Experts, both warriors or Spellcasters were all chasing after mastery over their Domain Space.
A Domain Expert could cast a powerful Domain Space and block off their enemy's perception of Magical Elements, limiting their use of external sources of energy. In other words, in their own Domain Space, the abilities of someone else would be greatly restricted. A powerful Magical Tutor might not be able to cast a fireball if they were in another person's Domain Space.