For all that Aqua has been to enough of these to know that things don't always go quite as intended, it's more than a little irritating to not have managed to get any of her attack to hit the Nightmare. There isn't really much she can do about the concentric rings of force that the Nightmare sends out though. Her shield is pretty good for blocking but she still needs a moment to bring it up. And if she did that as many times as she needed she wouldn't be very effective at attacking. Certainly not enough so to help take down something like this.

So she simply does her best to weather the attack as she very carefully lines her horn up to point directly at the Nightmare and concentrates. She might have been most used to having a Keyblade when she did attacks like these, but there was nothing saying that she couldn't also do so now. Especially with her horn being a decent enough replacement.

A brief moment later, a veritable barrage of poison-based projectiles shoot off in the Nightmare's direction. Whether or not the Shotlock actually will inflict poison is another guess entirely, but she's done the best she can, at the very least.