Ok, well, for anti-hail:
Gothorita @ Eviolite
Trait: Shadow Tag
EVs: 252 HP / 252 SDef / 4 SAtk
Calm Nature
- Calm Mind
- Psychic
- Rest
- Rain Dance
Gothorita puts a full stop to Hail teams, no doubt on this. I have succesfully tested this set with much success. You can just switch into Snover, use a couple of CM's (and continue if there is no Dark-types), get Rain Dance up and kill Snover. That will hamper most of the opponent's team, as Blizzard will end up missing more time than it hits, Hail stall would get much harder to pull off, and that's about it. Even outside of Hail, Gothorita can make a great Special Wall, can proceed to eliminate annoying walls such as Alomomola and Amoonguss (Beware, if you try to beat them, the game will become really long), and take care of Fighting-types that plague this metagame, such as Sawk and Gurdurr (CB Sawk does a chunk, though).
Best partner to this set is Ludicolo. He can benefit from Rain, and take care of some of Goth's checks. Bug-types and Specially Defensive Skuntank can do a lot to this core, so wisely predicting Skuntank switch-ins are required.