Nice idea! I know that this is rather picky, but the text of the card reads that creatures miss 33%/40% of the time, which does not follow the traditional read of Elements cards that creatures have a 33%/40% chance to miss. The way it is right now, it means that the creatures' attack successes are dependent on one another, and that one out of every three attacks is assured to miss in the case of the unupped one. Thematically, I would think that each individual creature would have a chance of missing independent of other creatures, so I would suggest changing the text to read that Airborne creatures have a 33%/40% chance to miss.