Natori, Sentinel Monk

Vigilance
When Natori, Sentinel Monk enters the battlefield, you may return target creature you
control to it's owners hand. If you do so, target creature you control to it's owners hand. If you
do so, target opponent mills a number of cards
equal to that creature's converted mana cost.
{1}{w}{u}, {t}: Discard a legendary card: Target
opponent mills two.