Mo Hua wanted to sneak past Lu Chengyun and Zhang Quan, secretly slip into the Ten Thousand Corpses Formation's altar, and he had to get through two doors.
One door was the door to the main hall.
The other door was inside the hall, within that mural.
The hall's door was easier to deal with, but the mural was a real headache.
For starters, he didn't know what hand seals or incantations Zhang Quan was using.
Zhang Quan wasn't about to reveal that, either.
Even if Zhang Quan told him, Mo Hua wasn't sure just mimicking him would truly open the mural.
That zombie mural, just like the Dry Ink Screen in the Corpse Walking Stronghold, should both be a kind of Spiritual Artifact that acts as a door lock.
If it's a Spiritual Artifact, then there ought to be a Formation inside.
This kind of Formation—not the Five Elements Formation—isn't in Mo Hua's wheelhouse at all.
Even if Mo Hua wanted to break it, he couldn't.
Even if he could, Lu Chengyun would surely notice.
