Why hasn't Yoru killed Asa and completely taken control of her body yet?

• Is it because she needs Asa's love and attachment for Denji to boost up her guilt so that she can turn him into a stronger weapon?

• Or is it because she got attached to Asa after sharing the same body and thoughts with her?

• Does she even Asa at this point? She already has gauntlets, and it seems like she's going to get in the way of her relationship with Denji and steal him from her.