In any other Water/Air deck, this would be a good card. I could definitely see this in a Desiccation+Sky Dragons deck.
In terms of the FG, there's no reason for Neptune to even need this. They basically have 3 Air marks, which is plenty of quanta for EEs and Shockwaves. Within 2 turns, they're able to play an Eagle' Eye, and can use it's ability the third turn with 2
to spare. In just one turn, 3 Shockwaves can be played.
EDIT: Now that the card has been changed to Blade Storm, do the copies appear out of thin air or do they come from the deck?