Theranil, the Shadow Assassin

Flying, first strike, deathtouch, phasing.
When Theranil, the Shadow Assassin enters the battlefield, create a treasure token.
{x}{b}{t} Sacrifice {x} artifacts, exile that number of permanents your opponent controls.
During your ending phase, Theranil, the Shadow Assassin phases out. While phased out, this card
is treated as though it doesn't exist.