I tried The Shimmering Effusion yesterday... but I even was not able to get to it. I collected keys but didn't manage to put them in pillars. It seems I must put each key in certain pillar. But room is so small that I have just 1-2 seconds before crowd of zombies and protectors surround me (I haven't slayer bow to kill them fast). I tried all keys in a row till one of them changes pillar color. I put two keys but when I came to put a key in the third pillar the first two changed color back to initial.