To obtain the If Walls Could Speak standard quest in Xenoblade Chronicles 3 Future Redeemed, interact with the graffiti on the wall just north of the Command Center in Colony 9. For this quest, you’ll need to head to the Echoes of Gran Dell Citadel landmark in the Aurora Shelf. Once there, head to spot shown in the map below to find graffiti on the wall.
Interact with it to receive Graffiti Hint B. This time you’ll need to travel to the Mt. Nagul Viewing Deck landmark in the Black Mountains then take the ether slide to reach the Argan Cathedral Ruins. Once there, head to the spot shown on the map below.
Inspect the graffiti on the wall next to the Grippen Vollgull to receive Graffiti Hint C. For this one, you’ll need to make your way to Vermilions Woods. If you’ve unlocked the Palace of Bal Attas secret area, fast travel to that then head to the spot shown on the map below. If you have not unlocked this, you’ll need to work your way down the ether slides on the eastern side of the area after starting at the ether lift in the Lakeside Grotto.
When you finally arrive at your destination, inspect the graffiti on the cliff. You’ll receive Graffiti Hint D, which gives the last location. For this one, fast travel to the Fallen Gate of Ulcaria in The Ragmos Desolation.
When you arrive, interact with the ??? magnifying glass to complete the quest.
As a reward, you’ll receive 5110 EXP, 1940 Gold, Accessory Unlock Kit and Gold Jewel.