Yume Nyaki/guide

Angel
Enter the halo door. Go north-west and interact with the angel in the square-shaped enclosed area. Go up and interact with the crystal.

Screwdriver
Enter the glitched blue and brown door. Go to the end of the path and interact with the smiling chaser. In the maze go: Down, second Right, Down, Left, Up, first Right, Down, first Left and Up. Interact with the child Nyasuki. Go up and the screen will fade. You'll get the effect after that.

Kid
Enter the plain orange-brown door. Go right and enter the doorway. Enter the blue archway. Enter the cave. Go up and enter the doorway. Go down and enter the doorway. You'll receive the effect after the cutscene.

Light
Gotten from interacting with the spinning NPC in Nyasuki's room.