substitute cards mtg DFC Helper Card | Lorwyn Eclipsed | Standard players cant cast spells or activate abilities that arent mana abilities.) Exchange control of target noncreature spell and target creature Sudden Substitution | Commander 2019

So, uh, yeah, he's kinda great

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

Somewhat uniquely though, it places a particular emphasis on non-basic land types

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)