For any Lugia, all you really need to do is bring out something like Arceus-Water or Fairy and pull a fast Toxic on it before it can Sub and it’s pretty easy to kill from then on out. Toxic versions are a useless team slot against Eternatus and Arceus formes with Refresh. Thunder Wave versions can be annoying especially if the opponent is loaded with bulky sweepers like Primal Groudon, Primal Kyogre, CM Arceus formes, and Zygarde. It’s very passive though since Aeroblast or Air Slash does -100 damage each turn. It’s pretty much Primal Groudon set up food too. If you have a priority user like Arceus, slap Recover (or better yet Taunt. Just use Taunt) and let that get Thunder Waved and swap it in every time Lugia tries to paralyze another teammate. Para is actually very beneficial because here being paralyzed will preserve PP. Aeroblast PP will go down very quickly and Air Slash does -200 damage. Chip can easily be healed up using Recover. And you can set up, forcing Lugia to guess between Whirlwind or Thunder Wave as you waste its PP. Lugia will waste the majority of its PP doing nothing, meaning it will eventually be forced out.besides taunt
my team does not get taunt
But the best counterplay is Taunt. If you put an Arceus- Fairy or Water on your lineup with Calm Mind, Taunt, and Recover, Lugia practically becomes your win condition since it cannot do anything if it’s Taunted, Aeroblast does no damage especially with Calm Mind boosts, and you just heal off the damage with Recover.