Hao Ren was not entirely sure if the cult members who performed the evil ritual were the ones behind the trouble in Beinz. However, their appeareance in a troubling situation during a troubling time was enough to implicate them of the strange phenomenon in Dragonspine Ridge. Even if he disregarded this, he was not going to sit by and watch these people perform a human sacrifice.
Hao Ren had been hiding behind Nangong Wuyue's mist barrier the entire time. The cult members were immersed in the their ceremony and did not expect them. Everyone was in a daze when Hao Ren lunged out at them. It was only when the MDT hit the man in the mask that they began to come to their senses. Someone shouted, "Heretic! A heretic is in the sacred temple!"