"But I'm just a yellow rank 2 runemaster, King Don"
In this world, every profession had its own way of determining the practitioners' level in various kingdoms, in other words, the way of determining someone's level in one kingdom might differ from another kingdom, unlike the cultivation levels.
Among the rank 4 kingdoms, most of them used ranks or levels to determine someone's achievement in their profession. For example, in Korrinth the higher level of rune mastery was rank 7 or level 7.
Each level was divided into three sublevels being yellow level, purple level, and red level. Yellow was the lower sublevel, purple was mid while the red was the peak.
Again the standards used in one kingdom would or might differ in another kingdom just like the currency.
"You reached this level without any resources or guiding Nikalas, you're born to be a runemaster"
