You’ll automatically receive The Ouroboros Power scenario quest in Xenoblade Chronicles 3 Future Redeemed during Chapter 4. For this quest, approach the Colony 9 Camp rest spot to trigger a cutscene. When it concludes, enter Riku’s workshop to trigger another cutscene. Afterwards, make your way to the Gotrock Oracle Ruins, which is a small island to the east of Colony 9.
Once you arrive, you’ll encounter the Level 37 Heidel Taos. Take it down! You’ll then have to take on Rex and Shulk only using Glimmer and Nikol. When you’ve accomplished this task, return to Riku’s workshop in Colony 9. The quest will then complete! As a reward, you’ll receive 2930 EXP, 1860 Gold, Lessons in Unity, vol. 10, 11 and 14.