Who Attacked the Widowed Sister-In-Law at Night?

Dear Detective, after Pangxi's husband passed away, he was attacked every night. Now there are several possibilities: 1. It's Kai Chujiu who refuses to call her sister-in-law 2. He is a hypocritical Wei Jianlong 3. It's Pu Yue, the personal butler 4. There are supernatural events Purpose: It is urgent to save the survivors