Tornadus expels massive energy from its tail, causing severe storms. Its power is great enough to blow houses away.
– Pokemon White Pokedex
Tornadus got a new Forme some time ago (May), the Therian Forme (its “normal” forme is dubbed “Incarnate”). It looks like a big green and purple bird, fitting I suppose, since it’s the only pure Flying type (not counting Arceus with Sky Plate).
Appearance-wise, I think I like this forme slightly more than the other one, but it still looks weird with a man-like face on the bird body. I call it the “old man bird”. Though compared to the other members of the Kami trio’s Therian formes, Tornadus’s isn’t the worst imo.
In the Therian Forme, Tornadus gets the ability Regenerator, which is a pretty good ability (especially since it can learn U-turn), but I think its normal ability of Prankster is better.
Stat-wise, it has the same base stats as its Incarnate forme; it gets more Speed and slightly more defenses at the cost of less Attack and Sp Attack.