I like the 2 damage to airborne creatures idea. Airborne still feels like it's not fully integrated into the game. Unless someone plays one specific card (Wings), it is entirely irrelevant, and I do think this card is underpowered, though just slightly. Wings is a mono card but it really requires
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or
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to work really effectively, since so many creatures are airborne. Obviously if airborne creatures were extremely easy to get rid of, Wings would be overpowered, but Thunderstorm doing 1 extra damage to airborne creatures seems like a reasonable buff.