Ummm, think this needs to be a rare. One sided, anti-regenerating, anti-indestructible wraith might need to be a mythic AND cost more.
Don't get me wrong, I like the card.
I see your issue, but you have to use another spell to actually get rid of the creature. It's 2 cards to kill all their creatures. The best you can get with this card by itself is not having the opponent block with that guy. Also, if it's the opponent's last creature, the aura does nothing at all. I can see it as a rare, but uncommon seems to me where it fits.