The sky outside had already darkened, the red Blood Sea spread across the entire sky, and droplets of blood rain fell from the air, stirring ripples on the protective barrier as if sulfuric acid had landed on it, wisps of white smoke rising like icy water droplets beating on red-hot charcoal.
Once the red liquid landed on someone's body, it immediately corroded into black, fire-like wounds, even causing death.
This was not an attack, but merely the Nascent Soul True Monarch adjusting the weather conditions and the flow of Spiritual Energy, creating conditions for a later, larger-scale attack.
Though Fourth Grade couldn't enter the world of the Third Grade laws, this type of high and distant attack was unaffected, provided that the Spell's intensity did not exceed Third Grade.