You find Usazum Shrine in Hyrule Ridge and you need to find the green stone to activate it.

Quest Location

This quest begins when you create a teleport at Uzasum Shrine.

How to Complete the Quest

The beam of light from the crystal will lead you to Satori Mountain Foothill Cave. Defeat the Hinox in that cave to get the crystal, then bring it back to Uzasum Shrine to complete the quest.