It's quite a coincidence when you have both water and Air magic available, and a hero with water skills... Well done if you used it. I don't see a reason to ban it, as it provides some benefit from water artifacts. IMHO.
http://screeny.ru/5464e16b36e55d543a0a7f52
http://screeny.ru/5464e1be36e55d543a0a7fcb
And in the first game, Toghanash wanted to attack me again :D, but I was planning to gather Air magic for the next turn.