It is said that only a select few trainers who have demonstrated their prowess and resolve in the face of a multitude of challenges are to be granted the gift of Mega Evolution. Therefore, it should come to no surprise that one of the most arduous gyms in the region guards such precious power. However, unlike most other gyms, this one has a twist: it is usually partaken in pairs.
Luckily, when the player walks up to the gym, the player's rival, Theo, is there in a new outfit suitable for the frigid climate. However, even though you are taking the challenge together, the puzzles (or trials) are to be completed alone until both parties reach the gym leader.
The player will enter a cave and are directed to the left path by an acolyte of the Dragon, whereas Theo takes the right. Most of the trials are pretty simple, albeit some require a little ingenuity on the part of the player as a trainer. At the end of each trial is another Acolyte who will test the player with their Pokemon before allowing you into the next trial. The trials must be taken all at the same time, but after completing the fifth trial, the player may warp out of the gym and return without losing any progress.
The trials are as follows:
1st (Trial of Strength): As it sounds, it is a Strength puzzle. Just push the boulders until you are able to get to the other side of the room.
2nd (Trial of Wisdom): A basic cave maze. Navigate around the rocks and reach the other end.
3rd (Trial of Adaptability): This is an ice puzzle, with some rocks to hop across near a waterfall.
4th (Trial of Faith): This is probably the most difficult (at least for some) trial in this selection. Just like the Vinoville Gym, you have to navigate an invisible path with a device on the side to briefly skim light across the path. One misstep, and you are sent to the beginning of the room.
To solve the first puzzle start by going 2 steps north, continue with 3 steps to the east, then go 2 steps north, then go 4 steps west, then go 2 steps north, then go 1 step east , and finish with 2 steps north.
To solve the second puzzle start by going 3 steps to the north, then 2 steps to the east, then 1 step to the south, then 2 steps to the east, then 3 steps to the north, then 6 steps to the west, then 1 step to the south, then 2 steps to the west, then 3 steps to the north, then 4 steps to the east, then finish up by taking 3 steps to the north.
5th (Trial of Truth): There is an open path to the final Acolyte. The Acolyte at the path's end challenges you to a battle where items are forbidden.
For defeating Vaeryn, not only do the player and Theo get the Apex Badge - which allows the player to use the HM move Dive - and TM 95 (Caustic Breath), but they both are granted a Mega Bracelet and a free Mega Stone for one of their Pokémon, which they can choose when the Party opens and it will show if a Pokémon can mega evolve with the word 'Able', similar to when a TM is booted up. If you do not have a Pokemon capable of mega evolution, Vaeryn will temporarily lend you his Mega Ampharos (With Thunder, Thunderbolt, Dragon Pulse, Volt Switch) for the battle against Theo, and you will not be able to receive a mega stone at all even if you return later with a capable Pokemon. All Pokémon are healed to ready them for the upcoming Rival Battle.
Immediately after receiving the free Mega Stone, Theo challenges the player to a battle. Your chosen Pokemon will be equipped with the new Mega Stone, returning any previous held item to your pack. It will be moved to the front of your party, which will be fully healed. Theo will immediately challenge you to a battle, leading with his Mega Stone-equipped starter. You don't have to actually win this battle, but you will still lose money on being defeated.