Avarice, Devourer of Wealth

When this creature enters the battlefield, sacrifice all artifacts you own. Then deal 3 + 2X damage to each enemy creature, where X is the number of artifacts sacrificed. Each creature you control gains +X/+X.
This spell costs {1} less for each artifact you own.
{4}: Return 2 artifacts from your graveyard to the battlefield.
{4}{b/r}{b/r}, sacrifice an artifact: Destroy target creature or planeswalker.