Rune thief

Tale IV (As this Creature enters and after your
draw step, add a lore counter. Until it has IV.
It can't have more than IV lore counters on it.)
Rune thief can't be blocked
When Rune thief deals combat damage to a
player, gain control of target artifact with
converted mana cost equal or less then lore
counters on Rune thief.