Expecting a lot of Weavile/Kyubs and trapping cores (Duggy / Zone) because the options for ice pokemon are pretty limited. I used the following core once when trying out nice teammates for Tailwind Zapdos. Not the best core ever but pretty fun to use when just laddering for fun:
Zapdos @ Life Orb
Ability: Pressure
EVs: 88 HP / 252 SpA / 168 Spe
Modest Nature
- Tailwind
- Hidden Power [Ice]
- Thunderbolt
- Heat Wave
Many people expect they can just switch in their Clefable or Hippowdon against Zapdos but boy are they wrong when they see LO Modest Zapdos. Because of Tailwind, Zapdos can run a +SpA nature which means it hits harder than LO Thundurus, with nice coverage in Heat Wave and an awesome speed tier after Tailwind. 168 Speed to outspeed Adamant Excadrill and almost every non-scarfed Lando-T and Kyu-B before a Tailwind. With a modest nature and LO, Zapdos is able to 2hko defensive walls like Calm Clefable, Mixed Hippowdon and Kyurem-B, who can all switch in against Zapdos when using the regular defensive set. Zapdos deals with pokemon like Slowbro, MScizor and Rotom-W which helps the big wallbreaker of the core
Glalie @ Glalitite
Ability: Inner Focus
EVs: 252 Atk / 4 SpA / 252 Spe
Naughty Nature
- Double-Edge
- Earthquake
- Freeze-Dry
- Explosion
Not gonna lie Glalie is pretty bad but if you manage to get in a situation where tailwind is up, Glalie can easily break through offensive teams while still being a threat to bulky teams with a 120 BP STAB move. Mega Glalie struggles with pokemon like Mega Scizor, Ferrothorn and Rotom-W, but the 2 other members of the core can switch in against these pokemon and get some damage off. Double-Edge OHKOs almost every offensive pokemon that doesn't resist ice, while Earthquake helps against steel types like Heatran. Freeze-Dry to break through Rotom-W, Manaphy, Slowbro etc. but because it is really prediction reliant, it is still necessary to have a nice check to these bulky water types in the back. Explosion if the Tailwind slaughter is about to end. Even pokemon that resist this are in danger of getting killed (for example: 252+ Atk Refrigerate Mega Glalie Explosion vs. 0 HP / 0 Def Manaphy: 275-324 (80.6 - 95%) -- 50% chance to OHKO after Stealth Rock)
Garchomp @ Life Orb
Ability: Rough Skin
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Swords Dance
- Earthquake
- Outrage
- Fire Fang
Though Zapdos can deal with pokemon like Ferrothorn easily, having no recovery and a stealth rock weakness makes it a really shaky check to these pokemon. Garchomp gives the core a second option to break bulky steel types, while also weakening Slowbro and Rotom-W for Mega Glalie. After a Swords Dance, Outrage OHKOs pokemon like Slowbro and Defensive Lando-T. Earthquake is for a nice secondary STAB that is more spammable in general because it doesn't lock you into one move. Fire Fang eats Ferrothorn, Mega Scizor and Skarmory, who can all switch in against Glalie and stay alive with Roost / Leech Seed. Even without a boost, LO Garchomp is a very strong pokemon. For example, Outrage does over 60% to Rotom-W, which means it is in range of Glalie's Freeze-Dry (or even Double-Edge after rocks damage)
Threats include pokemon that can prevent Zapdos from using Tailwind (when using these kind of teams I often use multiple Tailwind setters) as this core relies on the speed tier to break offensive teams. Pokemon like Weavile and Mega Diancie can beat this core without many troubles as long as they can prevent Tailwind from going up. Stealth Rock is also a threat because the core has 2 pokemon weak to it and without recovery they are easy to wear down. Clefable and CM Slowbro are annoying once they start boosting so an emergency check to them is also needed. Other teammates include other Tailwind setters, ways to deal with offense without a Tailwind up (Scarf Keldeo, Talonflame) and hazard control.