Nyx, Connoisseur of Murder

When Nyx enters the battlefield, exile target
creature until Nyx leaves the battlefield. Nyx
may become a copy of the exiled creature and
still retain all previous card abilities.
Whenever Nyx deals combat damage to a player, target player mills cards equal to Nyx's power.
{u}{b}{b}Sacrifice a creature- Nyx becomes unblockable until end of turn.