Decided to make some nominations here:
-> S: Zapdos is able to check so many threats in the metagame while being extremely difficult to be switched into itself. It's able to dismantle the classic Tomo+Libra cores, as well as being a reliable answer to Tornadus-T, Rillaboom, and Cawmodore. The Defog set is solid but nothing to write home about, but 3 attacks + Roost is insanely good right now in my opinion. It's extremely difficult to switch into even without SpA investment and it's basically free to click Volt Switch more often than not. The few mons that can switch into all 3 of its attacks still lose momentum against Volt Switch(with the exception of Zeraora); the most common ground types in the tier are Garchomp, Landorus, and Equilibra, the former two get roughly 2hko'd by Hurricane, and Equilibra can't threaten Zapdos while taking significant chip from Heat Wave. While Knock Off can be annoying for it to deal with, it can still be avoided for the most part and Zapdos can continue coming in and providing momentum for the team.
-> A-: Jumbao's unique typing and access to Trace make it able to check a variety of mons in the tier. Being a decently fast, offensive Fairy with a Ground resist is really great right now. Scarf Jumbao is a really great revenge killer with its Leaf Storm + Moonblast + Focus Blast coverage being very difficult to switch into outside of Slowking-G and Toxapex, and is also a great answer to SD Garchomp. Trace gives Jumbao some really unique switchins, namely, it can block Volt Switch from Zeraora and eat Magma Storm from Heatran and proceed to force them out.
-> A-: Heatran is still quite good, but I find that it's generally outclassed by Equilibra in terms of being a bulky Steel-type. While a Fire immunity is nice, Equilibra's Ground immunity is generally preferred, and the utility Libra provides in Doom Desire and Rapid Spin is typically better than what Tran provides. Equilibra is a lot less susceptible to entry hazards than Heatran is, and because of it, Libra can afford to take a Knock Off a lot better than Hetran can. Heatran is able to carve itself a distinct niche in its ability to trap mons with Magma Storm, but the prevalence of Slowking just makes it extremely difficult for it to make progress.
-> B+: Oh baby it's time for me to talk about Miasmaw! This mon has its notable flaws, but Miasmaw's unique access to Neutralizing Gas and First Impression provides a very distinct and valuable niche. While it does have some difficulties switching in, it can somewhat reliably switch in on two of the best mons in the tier in Slowking and Equilibra. While Slowking can potentially cripple Miasmaw with a Scald Burn on the switchin, Future Sight and Teleport are almost always preferable to click, and even then, Miasmaw takes very little from Scald, putting the Slowking user in a very poor position if the burn doesn't proc. Similarly, while Equilibra can get some decent chip on Miasmaw with Flash Cannon, Doom Desire or Earth Power are clicked way more often, and it's very possible the Libra doesn't have Flash Cannon at all. Even then, the current metagame has a plethora of offensive pivots that make great partners for Miasmaw: Zapdos, Kerfluffle, Krilowatt, and Barraskewda can all pivot out on a Regenerator mon and bring it in. Compared to other wallbreakers in the tier, Banded Miasmaw is still quite prediction-reliant, but that's not a huge issue thanks to Neutralizing Gas always gaining progress when forcing out a Regenerator mon. First Impression is also just a phenomenal move, acting as a surefire failsafe against most setup sweepers and fast mons in the tier.
-> S: Zapdos is able to check so many threats in the metagame while being extremely difficult to be switched into itself. It's able to dismantle the classic Tomo+Libra cores, as well as being a reliable answer to Tornadus-T, Rillaboom, and Cawmodore. The Defog set is solid but nothing to write home about, but 3 attacks + Roost is insanely good right now in my opinion. It's extremely difficult to switch into even without SpA investment and it's basically free to click Volt Switch more often than not. The few mons that can switch into all 3 of its attacks still lose momentum against Volt Switch(with the exception of Zeraora); the most common ground types in the tier are Garchomp, Landorus, and Equilibra, the former two get roughly 2hko'd by Hurricane, and Equilibra can't threaten Zapdos while taking significant chip from Heat Wave. While Knock Off can be annoying for it to deal with, it can still be avoided for the most part and Zapdos can continue coming in and providing momentum for the team.
-> A-: Jumbao's unique typing and access to Trace make it able to check a variety of mons in the tier. Being a decently fast, offensive Fairy with a Ground resist is really great right now. Scarf Jumbao is a really great revenge killer with its Leaf Storm + Moonblast + Focus Blast coverage being very difficult to switch into outside of Slowking-G and Toxapex, and is also a great answer to SD Garchomp. Trace gives Jumbao some really unique switchins, namely, it can block Volt Switch from Zeraora and eat Magma Storm from Heatran and proceed to force them out.
-> A-: Heatran is still quite good, but I find that it's generally outclassed by Equilibra in terms of being a bulky Steel-type. While a Fire immunity is nice, Equilibra's Ground immunity is generally preferred, and the utility Libra provides in Doom Desire and Rapid Spin is typically better than what Tran provides. Equilibra is a lot less susceptible to entry hazards than Heatran is, and because of it, Libra can afford to take a Knock Off a lot better than Hetran can. Heatran is able to carve itself a distinct niche in its ability to trap mons with Magma Storm, but the prevalence of Slowking just makes it extremely difficult for it to make progress.
-> B+: Oh baby it's time for me to talk about Miasmaw! This mon has its notable flaws, but Miasmaw's unique access to Neutralizing Gas and First Impression provides a very distinct and valuable niche. While it does have some difficulties switching in, it can somewhat reliably switch in on two of the best mons in the tier in Slowking and Equilibra. While Slowking can potentially cripple Miasmaw with a Scald Burn on the switchin, Future Sight and Teleport are almost always preferable to click, and even then, Miasmaw takes very little from Scald, putting the Slowking user in a very poor position if the burn doesn't proc. Similarly, while Equilibra can get some decent chip on Miasmaw with Flash Cannon, Doom Desire or Earth Power are clicked way more often, and it's very possible the Libra doesn't have Flash Cannon at all. Even then, the current metagame has a plethora of offensive pivots that make great partners for Miasmaw: Zapdos, Kerfluffle, Krilowatt, and Barraskewda can all pivot out on a Regenerator mon and bring it in. Compared to other wallbreakers in the tier, Banded Miasmaw is still quite prediction-reliant, but that's not a huge issue thanks to Neutralizing Gas always gaining progress when forcing out a Regenerator mon. First Impression is also just a phenomenal move, acting as a surefire failsafe against most setup sweepers and fast mons in the tier.