You've almost reached the end of the road. The final gym battle, in the Snowbelle City Gym, is the only thing standing between you and the Pokémon League. You'll want a solid Fire-, Fighting-, or Steel-type Pokémon before you try to tackle Wulfric and his gym trainers, as they all specialize in Ice-type moves. Stocking up on Ice Heals and Full Heals is a good idea before you head inside. 

The Snowbelle City Gym puzzle is straightforward. You're up against a series of trainers, one on each side of the gym. Beat a trainer and you'll gain access to a button. Step on the button and the gym will rotate, according to the color of the button you stepped on, and bring another trainer over to face you. You'll need to step on buttons several times to shift the gym into the proper configuration before you can proceed.

Start with the girl on your left.

Ace Trainer Imelda
  • Sneasel, level 54
  • Cloyster, level 55
Reward: 5,500 P

Imelda is not that bad. Her Sneasel doesn't hit hard, but it will usually hit first. Prepare accordingly. Cloyster usually wastes a turn setting up Spikes, giving you a moment to bring it down. Try not to switch Pokémon once the Spikes are deployed.

Push Imelda's button twice to gain access to the guy on the right side of the gym.

Ace Trainer Viktor
  • Delibird, level 54
  • Mamoswine, level 55
Reward: $5,500

Delibird is a weak pushover, but Mamoswine is pretty strong with its Ground-type moves. Flying-types are not a smart choice in this gym, so if your chosen attacker can't outpace Mamoswine and get a OHKO you may want something that can Levitate.

Hit Viktor's blue button three times so you can move back to Imelda's platform. The blue floor ahead has to be connecting the two bridges. Hit the pink button three times to create a bridge north, right down the middle of the gym.

Next up is the girl on the green platform, to your right.

Ace Trainer Shannon
  • Cryogonal, level 52
  • Piloswine, level 53
  • Jynx, level 54
Reward: 5,400 P

Cryogonal can be annoying with Confuse Ray and Recover, but it's ultimately limited to ice attacks. Use this fight to set up a strong attacker before knocking Cryogonal out. Once it's gone you'll face Ground- and Psychic-type attacks next, so choose something that can resist both. A Water-type isn't a terrible idea.

Leave the green platform stationary and run across to the guy on the yellow platform, via the green pathway.

Ace Trainer Theo
  • Beartic, level 54
  • Vanilluxe, level 55
Reward: 5,500 P

Both of Theo's Pokémon are pure Ice-types, and neither are terribly fast. Beartic also basically wastes a turn setting up Hail a lot of the time. You have plenty of chances to wipe them out with super-effective moves.

Hit the yellow button once, then hit the green button three times, so the green floor is lined up with the central bridge and the two adjoining platforms. This creates a path up to the Gym Leader.

Leader Wulfric
  • Abomasnow, level 56
  • Cryogonal, level 55
  • Avalugg, level 57
Reward: 9,440 P

This is a tough fight whether you're prepped or not. Wulfric's Pokémon love to set up Hail, either through Ability or the move itself, so unless you deploy something that resists Ice-type moves (namely an Ice-type, which is little help here) you'll be taking extra damage for most of the battle. A Pokémon that negates weather isn't a terrible idea. Abomasnow loves to use Energy Ball, Cryogonal likes Confuse Ray mixed with Ice Beam, and Avalugg is a Curse fan. Stick to offensive moves that hurt Ice-types badly and you'll get through this fight with some dings, but largely intact. Fire is your best bet for all three, especially Abomasnow.

Beat Wulfric and you'll earn the Iceberg Badge, allowing you to control Pokémon of any level. You can also now use Waterfall outside combat. You'll also receive TM13 Ice Beam. With this final Badge in your clutches you can now head towards your ultimate destination, the Pokémon League.