Just keeping it up for these few minutes had put a strain on him.
It was not a physical strain, but a mental one.
The Transparent World perceived everything within a certain radius around him far too clearly, flooding his brain with information that Kanzaki Kumo struggled to adjust to at first.
Kanzaki Kumo: Oh man, my head hurts...
So his next step was to wait for a thunderstorm while improving his mastery of the Transparent World. Once he could activate and deactivate it at will, he would work on controlling its range, rather than immediately extending it to its maximum when unnecessary and giving himself a literal headache.
After that, he would find a certain fellow born without emotions and say a few things that would leave a demon scratching his head.
After resting for a while and waiting for the discomfort in his brain to ease, Kanzaki Kumo tried entering the Transparent World again.
As the saying went, practice made perfect. Kanzaki Kumo had not felt any awkwardness even on his first attempt at entering the Transparent World, so naturally, he felt none on his second. He simply took a deep breath, calmed himself, relaxed his mind, and slipped into it naturally.
This time, however, he deliberately tried to control the Transparent World's perception range. Although he accidentally overdid it, shrinking a range that had extended beyond the entire Butterfly Mansion and Medical Department to less than a meter around him in one go, he had at least confirmed that he could control it himself.
And besides the perception range, there was something else: absolute control over his own strength.
That was what had originally motivated Kanzaki Kumo to master the Transparent World.
Or rather, he wanted to avoid being helplessly beaten the next time he met