I'd probably compare Tornadus-t to Snake in that it's hella powerful and very few bad matchups.
Originally Posted by Fat Lord of Bays
Now, what Tornadus-T has shown us is that Regenerator might just be a deal breaker on offensive Pokémon in general. Could you imagine if any of the Swords of Justice had it? Or anything that wasn't weak to Stealth Rock?
I don't really know if Regenerator is the main factor (Mienshao is Fighting-type and resists SR, but it's UU), but it's certainly one of the most broken abilities in the game. I think it's mainly just the sheer dominance he has in rain and the little cat-and-mouse game one has to play with Tornadus-t before you even get a shot off at at. I mean if it didn't have Regenerator then mons like Jolteon would checkmate it every time without worrying about hazard damage because the Tornadus-t (assuming you both just have SR down) is suffering them as well. But the fact that it can just take the game's momentum and just run with it is it's breaking attribute. I mean, we see what happens with his Incarnate form: great mon that can spam Hurricane with horrifying power, but it lacks the blisteringly high speed and Regenerator to truly be as effective as its Therian form.