It was said that no one could absorb more than three times their own mana capacity in external mana at once. Supposedly, doing so would make them explode, blowing them to pieces like a goblin land mine.
According to research conducted by the Falthrien Academy, the limit of non-source mana an ordinary living creature could withstand was two and a half times its own source mana capacity. Exceeding that amount would result in immediate death.
Between two and two and a half times that capacity, the symptoms were numbness throughout the body and a foggy head. At twice the capacity, the nerves experienced extreme pain. Beyond that threshold, the pain receptors stopped functioning, leaving the body numb and the mind clouded.
These were some of the fundamentals of magic Alleria and Sylvanas had taught him during this time. They insisted that whenever Yu Lin Bloodhawk absorbed mana, he had to stop once the amount reached his own mana capacity and he began to feel pain, then refine that power into his own source power instead.
They told him that when absorbing large quantities of external power, discomfort meant he had already taken in an amount equal to his own capacity, while pain meant he had reached one and a half times that amount. They warned Yu Lin Bloodhawk over and over not to be greedy. If he went too far, he would pass through unbearable agony into numbness, leaving his head foggy and his thoughts sluggish.
In theory, that state allowed the fastest possible absorption and advancement, but it was also the most dangerous. Without pain to warn them, and with their thinking impaired, people would unwittingly keep absorbing until they burst.
They told Yu Lin Bloodhawk that if he did not want to die, he must never rush ahead