Viability update!
In this update I addressed various recently discovered threats, Dragon Dancers and Pokémon commonly found on sun teams.
Hakamo-o (Tsareena) was added to C rank
Despite being able to abuse QM + Dragon Dance, and having access to high-powered STABs in Outrage and High Jump Kick, Hakamo-o has some flaws that hold it back. Chief among them is its low Speed: Hakamo-o hits only 409 Speed after a Dragon Dance, so even though it is immune to priority, it is relatively easy to revenge kill using Speed only. Hakamo-o is also helpless vs. Fairy-types since it lacks both Poison Jab and Iron Head. As of coverage, Hakamo-o gets Earthquake, Rock Slide, Play Rough, X-Scissor and Trop Kick, none of which help it with its weaknesses and/or is redundant with its STABs coverage.
Fraxure (Gallade) was added to B- rank
Fraxure shares with Hakamo-o being a Dragon/Fighting Dragon Dancer. However, Fraxure often outclasses Hakamo-o. Fraxure's advantages over Hakamo-o include more Speed (Fraxure, unlike Hakamo-o, hits a reasonable Speed tier at +1), much higher Attack, and Poison Jab. With boosted Poison Jabs, Fraxure can take out slightly weakened Fairy-types which would otherwise destroy it. However, Fraxure is very weak to priority, especially after Close Combat's Defense drops. Speaking of which, Close Combat is more spammable than High Jump Kick and does not miss.
Ponyta (Heliolisk) was added to C rank
Ponyta had notably fallen out of the radar after Uber's unban, but it takes a place on sun teams as a sun wallbreaker and Solar Power abuser. While Solar Power gives it a very short lifespan, STAB sun-boosted and Solar Power-boosted Fire Blast hits like a truck (hitting
405 BP). Ponyta appreciates Stealth Rock support to nail impressive 2HKOes, such as Wailmer x Toxapex (clean 2HKO after rocks) and Squirtle x Chansey (with Stealth Rock up it has to be at full health to take two Fire Blasts). While Fire Blast is selected 90% of the time, Ponyta can predict the bulky Water-type switch-in and nail it with one-turn Solar Beams. Ponyta even has good coverage, unlike most other sun sweepers, having access to Thunderbolt and Hidden Power Ice (even though it OHKOes most Gligar after Stealth Rock).
While Ponyta is ver strong, it has several flaws. Outside of sun, Ponyta is useless, only having a place in weather teams. Ponyta is also frail and has a very short lifespan due to Solar Power's recoil and a Stealth Rock weakness. Lastly, Ponyta falls just short of the 130 base Speed tier.
Larvesta (Leafeon) was added to C rank
Larvesta has been a key member of sun teams since ORAS. The main reason for this is its unique typing, allowing it to cross-evolve with Leafeon while keeping its Fire STAB, and at the same time gaining Grass-type STAB moves to take out Water-, Rock- and Ground-types, which would otherwise threaten sun teams immensely. Unlike other potential Grass-type Chlorophyll abusers such as Tangela, Larvesta can directly take advantage of sun powering its Fire-type STAB moves further. Larvesta is also one of the few physical sun Chlorophyll sweepers, and it is one of the fastest weather sweepers too at 100 base Speed.
However, like many weather sweepers, Larvesta is a bad Pokémon outside of sun. Its moves are weak outside of sun-boosted Flare Blitzs. Larvesta has also movepool problems: it cannot run both Knock Off and Swords Dance (and Leaf Blade is way too important to be dropped); and Flare Blitz recoil means it actually hates Life Orb, having to resort to items like Charcoal or Choice Band, but Larvesta does not appreciate being locked into one move, unlike many other weather swepeers.
I would like more discussion on the following, since they probably have to be ranked somewhere, but as of now I lack enough experience with them to accurately rank them:
Grimer-Alola
Arceus-Dark, Arceus-Fighting, and other support Arceus formes
