"You asked me once, what was in Room One-O-One. I told you that you know the answer already. The Thing in the Room One-O-One is the worst thing in the world. Everyone knows it. The thing that is in Room One-O-One is the worst thing in the world."
It could be interpreted in THEPRIS6NER episode of Checkmate, that Six is in Room One-O-One facing his worst fear.
It may not be Six as his own worst enemy, but in facing his own worst nightmare, Six conjures up the white mass of the Village Guardian!
"Then why do you conjure up this? Look Six, look up. Look at your fear, see what you create with it."
Be seeing you