Skyshard is hidden inside Bloodmayne Cave – public dungeon. Following northern coast of a river, you’ll come across a part of wood, distinct from other part of the map by glowing mushrooms and plants. There are six-legged spiders that crawl around the area. They can be found inside a nearby public dungeon as well.
When you enter Bloodmayne Cave, follow the southern wall of the cave. This way you can skip many creatures that habitat the largest cave room. There are many patrols inside, that you can come across. Keep progressing safely until you reach the last cave room. Inside the room, near a rock, beside red and blue mushrooms there is a +1 skill point piece collectible.
Bloodmayne Cave approach.
Bloodmayne Cave entrance.
Bloodmayne Cave entrance map location.
Sand Kingdom Moons - Super Mario Odyssey Power Moons