The Zanpakuto of the Soul Reaper world possessed all kinds of abilities. Even some weak Soul Reapers wielded Zanpakuto with extremely powerful abilities. Chazhu, which Shen Fei currently held, was one such example. It continuously doubled the weight of whatever it struck: one became two, two became four, four became eight.
This ability looked very simple, and Izuru Kira had not achieved any impressive feats with it. But that did not mean the Zanpakuto itself was weak. Izuru Kira had simply been too weak to bring out its true power.
Chazhu could only display its immense usefulness in the hands of someone powerful. Come to think of it, Zanpakuto were somewhat like Devil Fruits: the stronger the user, the more fully they could unleash their potential.
After becoming a Herrscher, Shen Fei rarely used the power of his Zanpakuto, but that did not mean he had forgotten it. He simply had no need to use it, just as he had no need to use his time abilities.
But now, the time had finally come. After Heroic Spirit ORT appeared, he had prepared to use a Zanpakuto. He had two choices: Chazhu or Ryujin Jakka. One hand holding Judgment of Shamash, the other Ryujin Jakka—he had considered fighting that way.
In the end, however, he chose Chazhu. Ryujin Jakka was powerful, but considering ORT's abilities, it clearly could not defeat it. Chazhu's ability, on the other hand, could buy them some time.
In terms of raw strength, the powers Shen Fei possessed were enough to handle most battlefields, whether against individuals or armies. The same went for illusions. Unfortunately, the enemies appearing later in the Lostbelts were all absurdly overpowered gods, which was utterly frustrating.
To use the Soul Reaper world as an analogy, he was merely a seated officer who