Question: why anjana killed pooja and yash?
Answer: Anjana is the one who killed Pooja-Yash so that Adi can be back to her & she knew about Pooja cheating on Adi. She herself confessed this to Sakshi today indirectly. And now, her new target is Zoya only because she has the potential to be the person who can Adi love to bepanaah level.