Was wondering about this myself, Like what if I ignored Cordelia rejoining in main event and just continued main sortie till the end. Since there was no option to annihilation arrow cordelia herself Lol, or not use it on grey. So I've read about grey supposed new game part 2 bond events (they don't show up in ally bonds, I only found them in gallery, might be bug or might appear in new game plus) in the one between Grey and Cordelia part 2 event, the persons in it is Verna and Cordelia talking about how verna has lifetaker powers, and verna states she copied his file and currently connected in a way and if she does not disconnect with grey the moment grey gets vaporized so quickly, verna will also suffer that fate. So that's the reason cordelia gave us the Annihilation arrow, to delete verna from that timeline lol. In the epilogue it states verna just vanishes after the lifetaker fight. So in your ending does cordelia suddenly appear and uses annihilation arrow anyway?