Metallic Infector

When Metallic Infector enters the battlefield, distribute four -1/-1 counters among any number of target creatures.
Whenever Metallic Infector deals combat damage to a player, put a -1/-1 counter on each creature that player controls.
{2}{p/g}{p/g}, Sacrifice an artifact with converted mana cost X: Distribute X -1/-1 counter among any number of target creatures.