Besides gaining a deeper understanding of flying swords, Xu Changxing unexpectedly discovered that he seemed to have developed a peculiar resistance to heavenly thunder as well.
He could now watch himself being pierced by the Light Sword with a relatively calm mind.
Even that soul-rending pain could be suppressed through sheer will.
Such a dramatic change had not come from his considerable talent for the Sword Dao, but because the Light Sword had purified the impurities in his soul as it pierced him again and again.
Moreover, each time the Greenwood Sword Projection pierced him, it left a trace of sword intent within his body.
This was somewhat like marrow cleansing combined with the imparting of cultivation. The process was hundreds or thousands of times more painful than normal, but its effects also far surpassed ordinary marrow cleansing.
At last, Xu Changxing guessed why his simulated self had left this inheritance behind.
In the previous simulation, that trace of killing intent in his soul had kept him from daring to swing the sword in his heart at the heavens, right up until he died of old age.
That was why he had wanted his successor to possess a clear soul and a lucid sword heart.
Although the sword heart needed constant dusting, the soul required no such trouble.
A pure soul could only be tainted under extremely exacting conditions.
Correspondingly, purifying the soul was just as difficult.
Among the ancient texts Xu Changxing knew, he had never seen a single method for purifying the soul.
Yet his simulated self had actually managed to purify the soul with a flying sword projection and had even incorporated it into his inheritance.
This meant that Xu Changxing, two thousand years in the future, had attained a terrifying degree of control over sword intent.