Ever since Lin Li went to the Black Rock Mountains, he experienced battles that most people had probably not encountered in their lifetime. The first significant battle to his ascension was the one against the Death Knights. Under the oppression of the Death Knights, and with the help of powerful potions, he touched the Legendary-realm's boundary subtly and exhibited spells that were up to level-21, like the Eternal Light Spell.
The greatest gain from that battle seemed to be the acquisition of the ten-odd Death Knights who came under his control. However, in reality, the biggest benefit that Lin Li had reaped was the enlightenment regarding the Legendary-realm, which many mages longed for in their lives. If the mages who were stuck at the pinnacle of the Archmage-realm could ever be fortunate enough to catch a glimpse of Legendary-realm and experience such enlightenment just once, they would definitely have a higher chance of breaking through to the Legendary-realm.