The conditions for using it were actually quite obvious.
'Cause and Effect' was not an ability that created something from nothing.
There had to be a complete set of causes.
For example, if Fang Xiao wanted to skip the process of refining the Primordial Chaos Sword Dao tracks just now, he had to meet three conditions.
The Heart Dao tracks and the unrefined Primordial Chaos Sword Dao tracks were the prerequisites.
Second, he himself had to possess the ability to refine Dao tracks.
Lastly, he had to amplify the thought of refining Dao tracks in his heart.
Only by fulfilling every prerequisite could he directly obtain the result.
Of course, it might also only skip part of the process.
This was precisely the limitation of 'Cause and Effect.'
Everything had its degree of difficulty. Whatever one gained, one would certainly have to pay an equivalent price.
Fang Xiao had used the Primordial Chaos Sword Dao tracks throughout his body to simulate the Heart Dao tracks. After using 'Cause and Effect' to refine just one Dao track, more than ninety percent of the Dao tracks within him had fallen silent.
Thus, the upper limit of 'Cause and Effect' depended not only on the difficulty of what was being done, but also on the number of simulated Heart Dao tracks.
If the matter exceeded that limit, it could not be accomplished in one stroke; only part of the process could be skipped.
At the same time, after using this ability, the Dao tracks would also fall silent as a result.
As for how long they would take to recover, Fang Xiao still needed to observe that.
But presumably, the time would not be short.
Therefore, using it continuously was impossible.
Of course, there was an even more crucial point.
With the Dao