Judging from the information in the Strategy Module's notes, the [Fallen Grime] attached to the Seraph's feather was clearly far harder to remove than the [Evil Grime] on the Holy Spirit Heart.
Zong Shen remembered that the [Evil Grime] back then had only required sixth-tier holy water to be purified.
But the current [Fallen Grime] required seventh-tier, or even higher-tier, holy water for purification.
Furthermore, its reaction upon contact with demonic power was completely different.
[Evil Grime] underwent a dissolving reaction with demonic power. Although the process was not fast, Zong Shen had tinkered with it several times before completely dissolving and absorbing the [Evil Grime], turning it into an unconventional shield.
[Fallen Grime], however, was not so easily dealt with.
Upon coming into contact with demonic power, it actually released toxins.
There was almost no sign of dissolution on its surface.
If he tried to solve the problem with demonic power, he would probably need at least a thousand attempts.
The toxins precipitated during that process alone would be enough to give Zong Shen a serious headache.
The safest and most reliable method was still to find a way to get a flask of high-tier holy water from the divine kingdom's Holy Temple.
Of course, Zong Shen could also try to profit from the reactions produced when demonic power or the Power of Holy Light came into contact with the [Fallen Grime].
For example, he could prepare it quickly and seal it in containers.
Wouldn't that be the equivalent of homemade poison gas bombs?
He could also use the Power of Holy Light's contact with the [Fallen Grime] to ignite blazing holy flames and attack his enemies.
In addition, he could try using the various elemental magics and see whether they produced any other reactions.
After all, even [Evil