As for a new Aqua power. . . perhaps some kind of boosting power, as she's pretty support oriented with healing and Telepathy for troop recovery and coordination, so making troops stronger, perhaps through her ice, seems plausible. Like, puts ice over someones gem and they feel empowered until it runs out and melts/shatters or the ice is destroyed, though should be strong enough to tank a hit that would shatter the gem it protects.