7 Lightning Energy: Emerald (Holo Rare, 104) $13.50 Technical And Electrical Emerald is an expansion that came out near the release of its game counterpart and, just like the game itself, this expansion is one of the best in the series
Even if the card comes up later in the game when someone doesn't necessarily need more ink, playing Sail the Azurite Sea is still a cheap way to draw a new card
That alone would be completely unfair, letting you use their resources to maybe Catcher stall them, using their Energies, etc
Sunfall A five mana exile-all-creatures spell is not terribly overcosted, and it has the upside of making a big-ol' token that becomes a creature for two mana whenever you want
Path to Exile has the best late game scaling of any spot removal spell and so you want other cheap removal to pair with it so that you might be able to use that over this in the early game