I agree that Tyrarantrum is a major threat to the current NU metagame right now. Adding to the aforementioned points, I'd just like to draw the analogy (if any of you play SM OU) of Tyrantrum to Zygarde in SM OU -- it is the #1 offensive threat in the tier right now, and failing to prepare your team adequately against it will ensure that your team will never rise above 1300 on the ladder. Tyrantrum's awesome bulk (relatively for this tier) allows it to set up easily, and with one Dragon Dance in its belt, it can easily OHKO most relevant Mons in the tier with its dual stabs and/or Z- Earthquake/Outrage. Sure, the majority of physical walls such as Rhydon and Steelix give it a hard time, but remove those few counters from the opponent's team and Tyrantrum finds an easy time sweeping. Tyrantrum is an offensive threat that I believe is even a cut above the other S-tier pokemons, Sneasel and Necrozma. It may even deserve a special S+ rank, don't you agree? It's not just on paper. In practice, Tyrantrum can run multiple choice sets, instead of the already dangerous Dragon Dance sweeper set, to disrupt opponents further. Definitely worth looking into.