Snap, Legendary Battle Bot

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)

Whenever another Artifact would be put into a graveyard, exile it instead. Snap, Legendary Battle Bot gets +1/+1 for each Artifact in exile.

When Snap, Legendary Battle Bot leaves the battlefield, create Junk tokens equal to its toughness.

"All assembly required"