Clair Obscur: Expedition 33 lives up to all the hype around it. The game boasts of a great main story, but also a good number of side quests that get you pretty useful rewards as well. Such is the case with the Hexga Side Quest, and in this guide, we will go through how to complete it by finding all the rock crystals.
Hexga Side Quest In Clair Obscur

After reaching Stone Wave Cliffs with the help of Esquie, you will encounter an NPC that also appears in the main story. The NPC will ask you to bring three rock crystals, which are inside the cave to your right. Giving in to its demand is how you will complete the Hexga Side Quest. The NPC will then ask you to put it inside its body. After inserting, you can grab your reward. The reward is a New Pictos that applies an auto shell; and gives you a good health boost as well. You can use this for three turns when in battle.
Rock Crystals Locations

Rock Crystal #1: Go inside the bottom of the cave, and if you are done defeating the enemies, you can spot the first crystal right ahead of you. Shoot the crystal and grab it.

Rock Crystal #2: The second crystal is going to be on the opposite side to your right. Climb up on the cliff towards your right and keep going to find it.

Rock Crystal #3: Now go back the way you came down the grappling line. At almost halfway, turn left and move ahead until you see an area with lights beneath where you stand. Go towards the light. You will then encounter an enemy. You will get the final rock crystal once you defeat the enemy.
If you are looking to get all the collectibles that the game has to offer, check our guide here on all collectibles in the prologue for Clair Obscur.