Two factors had the greatest influence on the power of a Life-bound Treasure:
The first was the spirit materials used when refining the treasure.
Generally speaking, the rarer and higher-grade the spirit materials, the greater the treasure's initial power after refinement, and the faster its power would grow.
In this respect, Liu Yu had come close to perfection. There was already nothing left to improve.
The second was how long the treasure had been nurtured after refinement, and whether its owner was willing to expend origin energy on nurturing it.
Most of the time, the second factor was even more important than the first.
After all, how good could an ordinary cultivator's spirit materials really be?
Even a treasure refined from top-grade spirit materials needed time and origin energy to nurture it before its power could gradually increase.
Under normal circumstances, no matter how rare its spirit materials were, a newly refined treasure could hardly surpass one nurtured for three to five hundred years.
The greatest weakness of the Setting Sun Golden Rainbow Spear at present was that it had been nurtured for far too short a time. It had not even been ten years since its refinement.
Even with the exceptionally rare golden crow powder added to it, it still needed the tempering of time before it could reveal its true edge!
Still, with several top-grade spirit materials incorporated into it, the spear's initial power was already considerable, matching treasures nurtured for one or two hundred years.
But Liu Yu generally set his sights higher, so he remained dissatisfied.
After ending the battle, Liu Yu put the Setting Sun Golden Rainbow Spear into his dantian and looked around.
The spiritual lights shining in the night sky were gradually fading, and the incessant booming slowly subsided.
For Golden Core Cultivators,