If an artifact theme is to become something that every cube can use to the best extent, then green is going to need to embrace artifacts instead of just blowing them up all of the time
It's still good today, and although on the Reserve List, it's just $2.49 over at coolstuffinc.com right now (Hint, hint)
Both of those cards untap permanents in general which includes lands, creatures, enchantments, artifacts, and even planeswalkers, but many cards specialize in specific permanent types
It is excellent as part of the package, but you still want at least one flexible piece you can hold up
And for the Korean releases it can only be found on the first six cards of the 20th Anniversary Legend Collection (LEC1) of May 15, 2019