The streak of black light was indeed the Demonic Marrow Flying Knife!
To elaborate, while this flying knife is exceptionally powerful and excels at concealing its movements, when it emerges from the void at such a close distance, it inevitably leaves traces—especially for great cultivators whose spiritual awareness has reached an unimaginable level.
Thus, Han Li first used the God Shocking Sting to strike the opponent's mind, causing intense pain and forcing their spiritual sense to instinctively retract into their body. Only then did Han Li summon the Demonic Marrow Flying Knife, which emerged from behind and swiftly sliced at the opponent's neck, easily taking their head.
The outcome was decided in just that fleeting moment.
Otherwise, even if Han Li employed other methods to deal with the opponent, it wouldn't be a simple task—likely requiring considerable effort!
