The current strength of the man in the black robe was suppressed by himself; he had to spare part of his strength to absorb and merge these Netherworld Ghost Qi.
Just like Qin Fang, who also needed a portion of True Qi to suppress the black-robed man's Netherworld Ghost Qi—fully absorbing it would only bring misfortune to Qin Fang himself.
The man in the black robe was the same; although he cultivated Netherworld Ghost Qi himself, these natural Netherworld Ghost Qi weren't to be trifled with.
If they weren't refined and were absorbed directly, the outcome would be tragic. Not only would he be unable to command these Netherworld Ghost Qi, but the wild natural Netherworld Ghost Qi might even lead his internal Netherworld Ghost Qi to "rebel" together.
If it came to that, the man in the black robe would regret it too late…
