After you roll past the statue - walk backwards into the wall co clip through. Might take a while to get used to. After that - traverse the OoB area right into the fight , where you need to mirror-shoot 2 Light Orbs.

BEWARE - after you climbed down from the mountains and touched the water - area behind you despawns and can't be rendered normally again, meaning that upon death & after checkpoint restart you will be at the beginning of the tomb and not being able to run OoB (mountains will be gone)

Works on 60 FPS (Tested on PC, VSYNC ON)