I agree with the Gardevoir, Azumarill and Ttar comments - I'm unsure about Gyarados. Azumarill is one of those Pokemon with a great combination of typing, bulk, and power. It can either hit hard straight off the bat or be a deadly Belly Drum sweeper, whilst simultaneously functioning as an excellent answer to some top tier threats like Tyranitar, Salamence, and Garchomp. It's bulk, typing and priority helps overcome one of its largest issues, its low Speed. It also has a gimmicky role as a Perish Song user with Sap Sipper. Tyranitar is one of those Pokemon that works very well but has solid counters (Azumarill, any Fighting-type), and many more checks - Mega Kang (it's PuP bait), Mega Mawile, Gyarados, Rotom-W. Tyranitar is also easier to handle once you know its set, which is relevant in a best of 3 metagame. For example, physical Ttars can be counter by Garchomp. It's great but not quite S-rank - A+ if there were subranks. Regarding Pyroar, send it to C-rank. It has a niche, but if you know what it's capable off, you can fend it off easily due to its poor bulk (bad enough that CB Talonflame has an almost guaranteed OHKO against it). Common Pokemon like Ttar, Mega Zard, Rotom-W, Gyarados and more don't have problems against it. Also for something using HP Ice for Dragon-types, it loses to Scarf Salamence with Hydro Pump - I know Hydro Pump not that common now compared to Stone Edge, but like Garchomp, it can still beat Pyroar with the right set.