The disciples of the northern sword immortal sect should be the ones holding on in the blood-red Mountain surrounded by the beast tide.
Outside of the beast tide, there were actually quite a few cultivators wandering around. They weren't cultivators of the northern sword immortal sect, and they didn't make any moves to stop the beast tide. Instead, they stayed far away from the beast tide. Their motives weren't pure, and it seemed like they wanted to loot a burning house.
Their actions made Li Tian wary. Because they were so far away, Li Tian couldn't tell which sect they were from, so he couldn't rule out the possibility that they were disciples of the demonic Dao.