Whenever Voltan deals combat damage to a player, you may return target artifact card with mana value less than or equal to the damage dealt this way from your graveyard into your hand.

{4}{W/B/P}: Transform Voltan, Lifelike Craftsman

Whenever an opponent sacrifices an artifact, create a Treasure token.

For each three artifacts that leave the battlefield, create a 0/0 colorless Construct artifact creature with "This creature gets +1/+1 for each artifact you control."