@Just someone from the universe She is a Primera, the highest rank amongst those who have powers. The emperor is also a Primera but as time goes on his power and influence weakens. Still he is able to exert some sort of influence on Lilith as a Primera and would be able to fully control her as shown in her "previous" life. On top of all that, the Emperor wants to also have full control of Enoch and with Lilith under his control the Emperor could have Enoch do anything he wants.
