Urza, Assailant of Phyrexia

When Urza, Assailant of Phyrexia enters the battlefield. Create X 1/1 colorless Myr artifact creature tokens.
Sacrifice a artifact: You gain 2 life.
{2}, Pay 2 life: destroy target permanent with {p/b}, {p/c}, {p/g}, {p/r}, {p/u}, or {p/w}. In its mana cost.