Scrapsteel Colossus

Delve for artifacts (Each artifact you exile from your graveyard while casting this spell pays for {1})
Scrapsteel Colossus enters the battlefield tapped.
Last strike, trample
{2}, Exile two artifacts from a graveyard: Put a +1/+1 counter on Scrapsteel Colossus. It has indestructible until end of turn.