I could see it showing up in small numbers in certain decks like White Weenies or Heroic for a little extra oomph, but probably as a one-of or two-of at best
Artifact mana rocks blue pairs naturally with artifacts and runs efficient rocks like Sol Ring, Sapphire Medallion, and Sky Diamond High Tide and burst mana spells that temporarily double or multiply mana from Islands enable explosive combo turns Untap synergies Dramatic Reversal, Turnabout, and Freed from the Real convert mana rocks and dorks into repeated acceleration Cost reduction effects like Baral, Chief of Compliance and Sapphire Medallion function as pseudo-ramp by making your spells cheaper Card advantage as ramp blue's deep card draw finds land drops and mana rocks more consistently than other colors Building a Blue Ramp Package Mono-blue decks should lean heavily on 2-mana rocks (8-10 pieces minimum) since blue lacks natural land acceleration
That's your second result
If youre playing the Elementals-build, with cards like Risen Reef, then Ephemerate shines as the deck has so many enter-the-battlefield effects that you can utilize
You can spend a mana any time to cast a dork in any graveyard for that mana
5-cost Sabo is another value card that activates his effect when he attacks