Batgirl #25, p. 24: "I'm Shiva. I can't be stopped."

This was one of a few pages that I picked up playing on the first word we ever hear Cassandra Cain try to say in her second page appearance in the NML storyline, as Barbara Gordon tries to teach her the English language: "Stop."

Here, just before their climactic fight in issue 25, Lady Shiva says, "I can't be stopped. But perhaps... ...you'd like to try."

There's a page just before this wherein Barbara Gordon tries (unsuccessfully) to stop Cassandra from fighting Shiva (Batgirl #25, p. 9), in which she reminds Cassandra that her grief over her dark past in no way justifies nursing a death-wish: "You were eight years old. You were raised in a bunker by a psychopath. You had no idea what you were doing. You were *eight years old* The fact that you've tortured yourself over it ever since *proves* what kind of person you really are. In time... you'll see that. For now, I'm stopping this."

The interaction ends with Cassandra's pre-emptive apology, followed by a nerve-strike, leaving Barbara powerless as Cassandra seeks her fate.

And long before this or her Batgirl identity, as we're only learning about Cassandra's abilities and her relation to David Cain, in Detective Comics #734, p. 10, she assumes a pose opposite Batman that triggers in him a memory of his former instructor saying to him, "I call this the suicide drill. Your goal is to stop me. You can't, but try."

This theme of "Stopping" -- stopping oneself in self-discipline, heroically stopping others who are killing, or even stopping those loved ones who are trying to to keep you safe, when your feelings of duty supersede them -- are essential to the character of Cassandra Cain.