Drop down further into the Pyramid, then turn around. The Splinter will be by the left of the door.
Head through and you’ll spot an area with what looks to be Scorn frozen in ice. The door will be in front of you, with the Resonant Splinter above it.
Head to the left side of the arena and look for a Resonant Splinter near a Sphynx-like statue. The door will be on the left side.
You’ll go past an area called Collection. The door will be across the room from the entrance, but the Resonant Splinter is hidden on a ledge on top of it.
Look for a Resonant Splinter on the left side of the room, between the second and third plates. Shoot it, then look across the room to find the door.
Once you get to the first room with the Resonant Splinter to control the platforms ahead, look to the left to spot the Splinter. The door will be to the right of the Splinter.
In the last room of the jumping puzzle (the one with the moving platforms), look for a Resonant Splinter in the back right of the room.
Head up the first set of stairs on your left, then jump across to a ledge on your left. Go to the edge of it, then look for a Resonant Splinter on your right. The door is behind a sculpture on the other side of the stairs you just came from, hidden from view. Hop on one of the statues if you have trouble spotting it.
Head to the topmost platform, then look for a crystal across from Rhulk’s platform. The door will be on your left (right if you’re facing the boss arena) to find the door. You can spot this location by noticing the marked door.