Zobimaru, the Vanisher

Zobimaru can't be blocked by creatures with
power 4 or greater.
When Zobimaru deals combat damage to a
player, exile target permanent that player
controls, then return it to the battlefield. It gains
Vanishing 2 (This permanent enters the battlefield
with 2 time counters on it. At the beginning of your
upkeep, remove a time counter from it. When the
last is removed, sacrifice it.)