Board Thread:Questions and Answers/@comment-13886763-20160426181210/@comment-24152851-20160501053215

Well even if that's the case, de-aging isn't instantaneous. You could de-age Diagon a few centuries and he'd still have more than enough power to kill Maltruant.

Actually amortal means something that can't be killed because they were never technically alive. While immortal means alive but can't die, it doesn't neccessarily mean they have to have been "born".