Blood-Soaked Corpse Wrapping was a trial for the body. You had to dive to the bottom of the lake to retrieve the key hidden within. Though you were not an alchemist, you still recognized that what lay in the lake was not only harmless, but a medicinal bath with excellent effects for body refinement. But since it had not been made by you, you had no idea what effects the medicinal bath would actually have.
To avoid this potential danger, you had Calamity Fire Saint Venerable test the medicine for you. If even Calamity Fire Saint Venerable, who was not much of a body cultivator, could emerge unharmed—and even dive straight to the lakebed to retrieve the key for you—that would naturally be best.
Calamity Fire Saint Venerable had once been the common lord of the "Jindushengyou Realm" among the Seventy-two Realms. You had later investigated information related to him. Though he had not cultivated his body, he had endured no small number of hardships, and his willpower should have been considerable. So even if there were side effects, he should have been able to withstand them...
When the Heart Puppet touched the lakewater, Calamity Fire Saint Venerable reacted violently. It would have been hard for anyone to believe that this convulsing man was a Quasi-Emperor powerhouse. But it was not over yet. Your command had been for him to enter the lake completely, so even though the pain was unbearable, the Heart Puppet still controlled that unwell body and jumped into the lake...
It had to be said that the Heart Puppet was truly obedient. Even in such circumstances, it still carried out your commands without the slightest deviation. The result, however, was that the Heart Puppet sank straight down the moment it entered the lake. The good news