(PS: Just a note: Why does it seem like the protagonist can win a fight in just a few strikes, yet has to drag it out with so many moves, making it look less overwhelming? Is the author just trying to pad the word count?)
Setting aside writing techniques and plot buildup, let's talk logic: The protagonist's opponents at this stage all possess Divine Skills, and these skills vary widely. Without knowing the opponent's trump cards, if the protagonist rashly goes 'Blood Explosion' on them, it could backfire:
For example, if Li Fei starts off by consuming 1,000 Blood Souls to unleash [Blood Rage], and then uses 4,000 Blood Souls with the [Refining] Divine Skill to convert it into power, thinking to himself that he'll take them out with one slash!
But the opponent has a [Thorny Shield] Anti-injury Divine Power, along with other Divine Skills to strengthen the [Thorny Shield] and enhance its counterattack ability. Li Fei slashes with 5,000 Blood Souls, only to be countered for 4,000.
