As you enter the dungeon, keep following the path to your left. Soon enough, you’ll enter the first large dungeon room. This area has giant stone pillars at the center. The shard is also here, hidden close to one of the pillars.
Enter Ebon Crypt dungeon.
Ebon Crypt Map Location.
Next to the giant pillar.
Exact location of the shard.
Sand Kingdom Moons - Super Mario Odyssey Power Moons