UR -> C
I'm a little surprised froslass is unranked, honestly. there are a lot of good dedicated hazard stack leads this gen but froslass carves out a unique niche as the only hazard setter that can also spinblock, other than... this dweeb? ->
TLDR: froslass has a unique combination of useful traits that make it a reliable lead. i think a C ranking alongside other solid role players like barraskewda, zard, and blissey is fair.
I've been using a pretty simple, standard set:
Froslass (F) @ Focus Sash
Ability: Cursed Body
Tera Type: Fairy
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Spikes
- Shadow Ball
- Ice Beam
- Destiny Bond
timid hits a great 350 speed and with a sash you almost always get a spike or two up at the beginning of the game. sball and ice beam are a great stab pair, threatening neutral or SE damage on everything not named kingambit. destiny bond is a great choice - even if you’re outsped, you click dbond turn 1 and you guarantee a spike or a trade turn 2.
out of all the dedicated hazard setters, it's got one of the better matchups against common removers. tusk can’t spin on you and doesn’t want the ice beam smoke, so you can get a spike or two up, destiny bond/sack and keep momentum up to prevent it from getting the opportunity to spin later. corv can defog, but doesn’t really want to 1v1 you with cursed body and dbond. cinderace can be annoying but you can try for a dbond trade against it as well. hatterene obviously doesn't want to take a shadow ball.
froslass works well on offensive teams that can capitalize off the momentum it provides early. mons that also don’t give tusk openings to come in and spin, like iron moth or specs pult, make for good teammates.
1600s-ish replays
https://replay.pokemonshowdown.com/gen9ou-1864578483-yiwutgh3ta097r2v7mch80howwa70rdpw
https://replay.pokemonshowdown.com/gen9ou-1872821706-agccdby1csj6rnm6o5xhg53w1k0l6irpw