Even from below, the impact of the structure, forged from Sea Heart Iron and other magic metals, could be deeply felt.
The bottom was equally smooth and intact, emanating a powerful energy field with almost no apparent weaknesses or gaps.
Duke placed his hand on the outer wall of the underground vault and could distinctly perceive the flow of energy within.
It was also clear that the outer walls of this vault were indeed made of Sea Heart Iron.
Duke then began to slowly absorb the Sea Heart Iron within the outer wall using the Yellow Sand Crystal, at an extremely gradual pace.
He intentionally controlled the speed to avoid any rapid changes that might alert the people above.
As he absorbed, he observed and noticed no significant changes in the underground vault.
The absorption process of the Yellow Sand Crystal was extraordinarily wondrous, not achieved through some kind of magic, but more like a physical form of absorption.
