To obtain the Regret and Resolve standard quest in Xenoblade Chronicles 3 Future Redeemed, speak with Jethro just north of the Gelgemos Garrison in The Ragmos Desolation. For this quest, you’ll need to retrieve the keepsakes around the area.
Brass Locket
Tarnished Ring
Bloodied Bandana
Once you’ve retrieved the keepsakes, return to Jethro to hand them over. A Keves Patrol Squad will show up. Defeat the 6 of them to complete the quest. As a reward, you’ll receive 3270 EXP, 2240 Gold, Detector Headgear and Engineer Gloves.