User blog comment:Zolnir/Ozpin: The Age Immortal Headmaster/@comment-25045079-20140826002032

I had this idea that he had a Vampire Semblance, which leached Aura off others to sustain his own Aura thus keeping him alive, and if he spent too much time around adults, he would sap all their aura away and it would kill them, but maybe youner people have soo much of it they are for the most part unaffected.