After all, what we see here is a superheroine, Aura, murdered for no other reason than to demonstrate that the villainess of this story is both evil and dangerous.
Aura wasn't attacked to show how badass the villain was but because Repulse was hunting down heroes with powers similar to Aura's. If it had been how you say or done only to get Aura's former teammates to come into the picture you might have something though as is I'm not seeing it.