When Ye Xiao started to devour, what Lin Hao saw was the scene that was happening on the surface but unknown to him, Ye Xiao's true target was not the giant human and the black Qi but the world inside his body.
Ye Xiao was actually trying to devour the giant human's world.
Previously, when Ye Xiao merged with the Heaven Devouring Divine Dragon, he got the ability to devour anything, to be more accurate, any particular thing.
It was the first time he was trying to devour any particular thing but it was also the most dangerous part, he was actually trying to devour the world of the giant human that can only be created when one is going to become an Immortal.
Currently, Ye Xiao was only a Martial King Realm martial artist but he was actually trying to devour the world that was the source of power for any Immortal levelled cultivator.