Kage, Souzou, In (影・想像・陰)/guide

Light
In nexus interact with the red object/stone plate, go south-east to the big red soil field, find yellow cube in the middle of field, and interact with it to get effect.

Song
In nexus interact with the brown object/stone plate, go approximately/roughly south-west to the small maze, navigate your way to the middle of small maze, interact withy the blue cube to get effect.