Su Mu carefully examined the fist-sized stone in his hand.
The stone was irregularly shaped, as if it had broken off from a larger rock. Its texture was like crystal, but not completely transparent, with gleams flowing inside like blood vessels.
Directing his Divine Sense into the stone, he discovered a close connection between the stone and the stone door before him. Holding the stone, with a thought, the stone door began to shrink and merge into the stone.
Once the stone door merged into the stone, a tiny stone door could be seen embedded within it.
It seems this stone is the "key" and "authority" of the massive stone door, allowing one to control the door using the stone.
Su Mu waved his hand, causing the stone door to reappear, landing in the waters before him.
As the stone door descended, a small vortex began forming at its center, expanding at a visible speed.
It appears that the vortex can be confirmed as the result of the stone door.
