User blog comment:Crimson and Darkness/Volume 24 discussion blog/@comment-73.57.25.92-20180111180147/@comment-175.139.25.169-20180112063154

Pretty sure its mentioned that vali's talent for magic comes from his lucifer line and his mother was just an ordinary human

Wonder if Vali would get a power boost if Issei threatend to kill his mother and half siblings like how vali did in vol 4