Azaroth knew it would be a bad idea to kill this elder as it would alert the entire Black Lake Sect that there was an assassin in the vicinity.
Azaroth left the location after erasing parts of memories from this man's head. This man had no idea that something had happened after his comrades left.
He would think that he was quite tired and fell asleep on his bed.
Meanwhile, Azaroth had gone to find Christina. It would be easy to bring Christina to the camp using Tiana's name.
If he had Christina at his camp, the situation would be under his control. Whether it was the timing or the result. He would choose the one most favorable to himself.
Having Christina at his camp meant that his camp might become the primary target for the Night Mountain Sect. Tiana's group was completely wasted, and they could no longer fight for this one week.
