Hi, so my friend and I battle quite a lot in Pokemon Scarlet/Violet, and try to improve off one another's teams. But the thing is, he recently came up with a Doubles strategy that I cannot beat no matter what I do. He uses Chansey and Volcarona to sweep my team. Since we're good friends and battle often, I have the details on the sets he uses, which I'll show below (with permission) for reference.
Chansey @ Eviolite
Tera Type: Dark
Ability: Healer
EVs: 252 HP / 252 Def / 4 Sp. Def
Nature: Bold
-Heal Pulse
-Life Dew
-Defense Curl
-Focus Blast
Volcarona @ Leftovers
Tera Type: Electric
Ability: Flame Body
EVs: 252 HP / 252 Def / 4 Spe
Nature: Bold
-Quiver Dance
-Fiery Dance
-Bug Buzz
-Giga Drain
So, the first issue here is that Volcarona has solid HP/Defense, so I cannot break through it Physically before the Chansey can use Life Dew/Heal Pulse; that plus the Flame Body ability and Leftovers makes my physical attackers unable to do much to it. If I bring Rock-Type moves for the 4x weakness, he Teras to Electric, and he has Giga Drain to deal with Rock-Types anyways. Without the STAB boost, my Rock moves don't deal enough anyways, and with them, it can use Giga Drain (same with Ground when he Teras). Also, he can use Quiver Dance multiple times with me hardly making a scratch, making him faster than anything and able to OHKO my entire team, and on top of all that he gets Sp. Defense boosted to be invincible that way as well.
Then we have the Chansey, which is ingeniously built with counterintuitive physical bulk, meaning I cannot OHKO (or even 2HKO) it, even with powerful Fighting-Type moves. This means that when it uses Life Dew to heal Volcarona, it heals itself as well. If I have a Knock Off user to remove the Eviolite, he will use Defense Curl to essentially put the Eviolite back on, and if I use Taunt, it uses Focus Blast. A Taunt strategy is the closest I can get, since Focus Blast is only 70 accuracy, and that negates most of Chansey’s use, but even when I do this, it means I’m so focused on the Chansey that Volcarona can get a Quiver Dance in, allowing it to sweep my team.
So in short, when I focus on Volcarona, Chansey just heals it up; when I focus on Chansey, Volcarona sets up for the sweep; and when I divide my focus, nothing happens. The only strategy that has beaten him online has been a Rapid-Strike Urshifu (with Tailwind active), which can OHKO Volcarona (technically 3 hits, but one move in Surging Strikes) even with one Quiver Dance in, but I don’t have Urshifu and don’t like using legendaries anyways.
Any suggestions for a hard or even soft counter?