You mean when Shiva said "I gave you life 3 times"? The first was, obviously, giving birth; the second was in the storyline where this empathic metahuman somehow rearranged things in Cass' brain so that verbal communication was less difficult for her (this is in the second TPB, IIRC), but the problem was that that messed up her ability to fight in that I-can-read-your-every-move way, so Shiva came to her and basically said, I can teach you to fight the way you used to, but if I do, you must agree to meet me in 1 year (I think it was a year -- or was it less?) and we fight to the death. Shiva actually did kill Cass, but used some weird mojo (or phlebotnum) to bring her back to life. And then the third time was this time, thanks to the Pit.
t edit Or, what ita said. With fewer words.