User blog comment:MyProjectAlicization/Kuroyukihime - Kirito and Asuna's daughter?/@comment-24034641-20131125043404

there's also speculations that Kuroyukihime knows Kirito and Asuna's child, this is because of her two skills Starburst Streak and Vorpal Strike, as those two skills were actually taught to her by her friend Graphite Edge, however we don't actually know much about him. I personally prefer this speculation as the similarites between Graphite Edge and Kirito are quite high, Graphite Edge's Enhanced Armament is "Twin Swords" and his stats that are known are quite similar to what Kirito would of had.