And on the fragments of this corpse, they found no silver nails, so it was probably not a Mars MM, but more like a spy or secret agent of some sort.
Li Pan also casually touched the door and could feel an astonishing amount of Profound Dark True Qi flowing through his meridians into his hands, filling his lungs and viscera instantly. Clearly, the source of the True Qi was behind the door, and indeed it was not something an ordinary person could withstand.
He tried pushing the door, but it wouldn't budge, and now Li Pan only had one silver key left. If he went through, he feared he might not be able to come back, and he was quite conflicted for a moment.
However, after thinking it over, Li Pan didn't want to have come all this way for nothing. Since there was an abundance of Profound Dark True Qi, he sat down at the doorway, silently recited the Heart Sutra, and projected his Primordial Spirit out to explore the other side of the door.
Very quickly, whoosh, he crossed over.