If a Level 5 Adventurer were to step inside, the Restriction alone would be enough to trap and kill them.
Even a Level 6 Adventurer would have a hard time escaping for a while.
As for why it couldn't kill a Level 6 Adventurer…
The materials available on the market were limited, and Array Formation was far more difficult than Array Disassembly. Considering Lu Cang didn't even have the Array Master Profession, being able to achieve this without any related class was already an impressive feat.
"The Eternal Frost Bow and the Bone-Freezing Body-Piercing Battle Spear."
Lu Cang didn't know how to use a bow, so he could only wield the War Spear.
In the basement, he swung the War Spear, leaving a trail of frost in the air.
'This weapon…'
'It should be no weaker than a weapon made from the materials of a Tier Six Submerged Land Level Demon.'
'No, it's even stronger.'
The Backlight Boots.
A pair of combat boots etched with countless flowing golden runes.
