Why does he want Veer dead? He only wants Bani’s powers right? Just take her powers and leave. By the way how did Veer know that Jay is AdiNaag?
In some last episode it was shown that jai was talking with markat shaitan and they discussed that on full moon night veer will remember everything about his past and he will be the most powerful creature. That's why he don't want veer to become powerful and wants to kill him.