Scrap Salvager the Ruin Walker

Myr you control have haste.
At the beginning of your upkeep, sacrifice an
artifact. If you can't, exile Scrap Salvager.
{b}, {t}: Create a 1/1 colorless Myr artifact
creature token.
{b}{b}, Sacrifice an artifact: Put Scrap Salvager
from exile into your graveyard.