This card is interesting, but I wouldn't use it in an Aqua deck. I would toss it into decks that are likely to accumulate recruits and possibly gems more easily than a deck with a focus on Aqua, maybe along with another Common Aqua or two. I'd then use it when there is another Aqua in hand and when I have 20-30 recruits so I can play the summoned card and then the other Aqua for the keyword effect. This would go great in my Unliving deck for this purpose. Brigand, Nature, and Restoration already have Commons that share the Aqua keyword, so this could potentially get some use for those as well.