The icy queen leads with her Dewgong. It has Waterfall, Ice Shard and Aqua Jet like before, but can now use Iron Tail. However, this additional move doesn’t really change much. Ideally, you should fight it with strong Electric or Fighting-types.
New to Lorelei’s roster is the Alolan Sandslash. Because of its unique typing, it takes massive damage from Fire and Fighting. For attacks, it has Ice Punch and Iron Tail for STAB, Ice Shard to go first, and Earthquake to scare Fire-types. It’s slow so you should be able to one-shot it before it causes any damage.
Cloyster gains Poison Jab and Blizzard, on top of its previous Hydro Pump and Spike Cannon. But you shouldn’t be using a Pokémon that Poison Jab is strong against. Like last time, any strong special attacker can do the job; Electric and Grass ones are best.
Lapras, Lorelei’s strongest Pokémon, can still be a pain to deal with. It can still use Hydro Pump, Blizzard and Dragon Pulse, and has gained Thunder to counter opposing Water-types. Electric and Fighting-types are highly recommended.
Slowbro remains the odd piece of the puzzle, since it’s not an Ice-type. Anyway, it can still use Surf and Psychic, and carries Fire Blast in place of Flamethrower. The biggest change is Yawn, which can cause sleep on the next turn. Electric and Dark-types are the safest choices, especially if they’re special attackers.
Finally, we have Jynx. It can use Shadow Ball in addition to its original arsenal of Blizzard, Psychic and Lovely Kiss. This allows it to hurt opposing Psychic-types, but we can’t imagine you using one. Go with Fire or Steel-types if possible. Or Rock-types if they’re not weak to Ice.