Dense and thick waves of aura of death were contained in Su Ming’s body right at that moment. That aura came from the World of Nine Yin, from when he persevered and finished watching the ancient bronze sword leaving. He saw the world outside the mirror, saw the spherical balls in the galaxy, along with the numerous continents floating there, and during that moment, because his body could not get used to the world out there, he had gradually began to rot, and dense waves of aura of death spread out from all over his body.
Perhaps this aura of death had always existed in his body, but had only revealed itself when he had been in the world out there.
Even after Su Ming was relocated, some of that aura of death still remained on him!