Volc was used on stall a lot historically.
In SM, it was done to check Grass Spam (Rilla + Kart) and Mega Mawile — MMaw in particular was hard for these teams to handle otherwise. It did mandate multiple Defog users back then.
With Boots in SS, it became a better option on stall as a win condition that resisted fairy, Grass (similar matchup dynamic to prior gen), and was less reliant of support. It was able to help with some longer games. It didn’t always fit though.
In SV, Volcarona was B- on the Big Stall Stall Viability Rankings before it was banned. It was mainly for role compression as it soft checked certain Kyurem, Valiant, Enamorus, Rillaboom, etc. while making Gambit and other physical attackers think twice about clicking contact moves. The image below is taken from their server from earlier in 2024 before the ban. It was definitely better on HO than Stall, but it saw a ton of usage on BO and even some on balance as well. Volcarona was never archetype locked (maybe in BW at times, but even then not fully).
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