Capítulo 1032: The Forsaken One

Ace questioned the system about this new situation, "System, why can't I comprehend Darkness any further? Is 50% the limit?" 

"[System has already told the host that the comprehension of darkness is related to the branches of darkness. You will naturally progress as long as the host comprehends more branches of darkness.]

Realization dawned on him as he had already seen that all the laws related to darkness were at 99.99%, so unless he made further progress or comprehended other laws related to darkness, he wouldn't make progress. 

The Darkness Comprehension was different from other laws because he only awakened it after getting the first order of darkness. Now, he also managed to awaken a vastly different rule than a mystic ability.