Scrap-metal Mechanic

{ut} Sacrifice Scrap-metal Mechanic: You may return
any number of non-creature artifacts from your
graveyard to play with total mana value less than or
equal to 5. These cards may only be black or blue.
When Scrap-metal Mechanic enters or leaves play, tap
or untap any non-creature artifact. This ability is not triggered if Scrap-metal Mechanic was sacrificed.
If this card would enter then graveyard, exile it instead.