Evolution requirements
During the last three months, Jason had diligently practiced all of the techniques. He religiously continued improving his mana absorption, his Heaven's Hell practice to receive more soul energy units, his body refining with the Netherworld's fort technique as well as his martial art and affinity practice.
Thus, his whole day was jam-packed and it was only fortunate that he could passively absorb mana which however didn't mean that he forgot to actively absorb mana as it was much more efficient.
In the end, Jason just slept less, at most three hours a day, yet even that period seemed to belong for him in recent days.
He just didn't feel the need to get more sleep and felt vigorous enough to work for days with the nutrition and mana inside him.