After you search for Condé's big brother in Lanayru Temple, you find Skorchill.

How to Defeat Skorchill

First Phase

Skorchill will slam his fists into the ground and stop like that for a moment. Sometimes Skorchill will stomp on the ground, which makes icicles fall from above. Then Skorchill will spin around while sliding back and forth. If he bumps into you, you will temporarily be frozen.

Use fire monster echoes to hit Skorchill's helmet. The Fire Wizzrobe echo works well. This will break an ice horn off of the helmet. After all of the ice horns fall off, bind to the helmet and pull it off of his head. Then hit Skorchill repeatedly.

Second Phase

Skorchill will put on a new helmet that has flame horns. He will sometimes spit fireballs at you, one after the other, so keep moving to avoid getting hit by a fireball. Sometimes Skorchill will take a deep breath, then spit out a large fireball that turns in to a flame tornado. The tornado doesn't move, so just stay away. As before, sometimes Skorchill slams down his hands and stops there for a moment.

This time, use ice monster echoes to hit Skorchill's helmet. The Ice Wizzrobe echo works well. This will break a fire horn off of the helmet. After all of the fire horns fall off, bind to the helmet and pull it off of his head. Then hit Skorchill repeatedly.

Third Phase

After this, Skorchill puts on a helmet that can switch between fire and ice horns. If there are ice horns, use fire attacks to destroy the horns, and if there are fire horns, use ice attacks. Skorchill will use a combination of the attacks you have seen throughout the battle.

After the Battle

Afterward, there will be a cutscene. Tri's level gauge will increase. You will receive 5 might crystals. There will be an additional cutscene after this, and you will receive Lanayru's Sanction.

Take the Heart Container (or leave it there for an extra challenge), then go to the glowing spot and talk to Tri, and say Yes if you're ready to exit the dungeon. There will be a cutscene. This completes the quest "Rift on Holy Mount Lanayru". If you have received the Sanctions from the the other two goddesses, there will be a cutscene that begins the next quest, The Prime Energy and...