The people of the six realms had also realized that there was one force in the void realm that they could not afford to provoke, and that was the underworld. The people of the six realms dared to provoke the five great families because they realized that the five great families were not that difficult to deal with. Even if they provoked the five great families, they would not necessarily be in trouble.
However, if they were to provoke the underworld, they would definitely be courting death. The underworld was different from other powers. For other powers, they might not care about the death of one or two cultivators and would not even investigate. However, the underworld was different. They would investigate the death of any cultivator and if someone was killed, they would pursue that person relentlessly. This was why no one dared to provoke the underworld's cultivators.