substitute cards mtg DFC Helper Card | Lorwyn Eclipsed | Standard Then the spells controller may choose new targets for it. MtG 2019 Commander Rare Sudden

With other complementary artifact mana sources like Thran Dynamo and Grim Monolith, decks could count on being able to get the kind of mana you'd need to justify packing the cards that would let you use the mana from Metalworker to deliver the knockout blow, and their presence lets you turn that Metalworker mana into permanent giant amounts of mana rather than just a one shot deal

In terms of effect this is about as it gets for green

And thats something most split cards arent

It gets +1/+3 until end of turn

Some oversized cards were used at the Massive Magic Tournament hosted by people from Robot Chicken and held at Pro Tour San Diego (19?21 February 2010)