Zheng Yichen had never experienced a breakthrough in battle, he did not tread the path of cultivation that led to sudden enlightenment, and his progress during combat mostly relied on using and understanding his extraordinary abilities and the power he had mastered.
The new understanding and use of his strength allowed him to launch stronger attacks, and he did not need to maintain Oblivion for long, as that state also had an impact on him, and it was difficult to ignore such effects through mere improvement in his own strength.
Abilities like Burst Mode, with the enhancement of his physical fitness and strength, the consumption that came with it was no longer a burden to him.
It was only the recently reached third stage of Burst Mode that brought about noticeable consumption.
Utilizing Oblivion combined with Earth Devouring was an effective way to avoid such burdens.