At this depth, the sea was entirely pitch black.
But Fang Yuan's vision was dark green.
"Alright, this new Gu that I exchanged for is quite useful, with it, I can barely see in the deep sea." Fang Yuan was quite happy.
The deep sea was complex, one could not shine light here carelessly, or predators might be lured to oneself unknowingly.
In this dark green area, there were some deep black patches.
They were black oil of course.
The black oil tangled and weaved together like huge pythons. They were almost still, but the visual impact was huge.
Fang Yuan breathed in deeply, the gills on his face moved as they took in oxygen from seawater, allowing him to breathe underwater.
Calming down, he carefully approached the black oil. He stretched out his arms and stopped when he was several meters away from the black oil.