Never mind. Today instead of tomorrow. A lot of things can go wrong in this scenario. Also, the elf/human split could have been entirely coincidental or Einar's choice-decision of Einar's creator. Of course, others might not see it that way...
“Can a magician kill a man by magic?” Lord Wellington asked Strange.
Strange frowned. He seemed to dislike the question. “I suppose a magician might,” he admitted, “but a gentleman never could.” — Susanna Clarke, Jonathan Strange & Mr Norrell