Thundurus-Therian should be listed as a stallbreaker. With Pokémon like mew, gliscor, and kartana in the stallbreaker section.(each of them losing to common stall mons the former losing to mega sableye unless Sableye gets outplayed insanely. Gliscor loses to the combination of Sableye switching in and out, and if skarmory is present on the team going into that, only losing to taunt knock Off. Zapdos is a reliable check, but not all stall teams have it. It is not that hard to ppstall. The latter gets easily revenge trapped by Dugtrio.) Using the same standards I believe Thundurus-T is worth to be a stallbreaker with set up. It does have a hard time breaking clefable, but thunderbolt+ z thunderbolt koes. It can easily break past chansey later in the game and isnt trapped by Dugtrio. Quagsire gives it a really hard time, though.