Wang was not merciful as his spear spun in his hands before being thrust and the power it brought along with it was very destructive. No one survived when they were targeted. Elder Li was the most unlucky, as he did not expect Wang to be that fast and the trump card he had, was employed late resulting in it being knocked out of his hands and what followed him was a spear thrust into his chest.
By the time he left, the group's property had been cleaned up completely leaving behind nothing of value while he had close to 413 contribution points at the moment. He did this intentionally when the elder Li showed the unique tiny stone pillar with inscriptions. He then picked up the thing that dropped from the old man's hands before leaving the place.