Misinterpreted. Those are two suitable words to describe what really happened. Lucia has indeed prepared and activated a unique artifact that can lock Shadow's power and system for a certain period of time.
However, on the other hand, Shadow's silent body is not his natural body. It was just a clone that he had prepared long before they entered the last floor. Shadow has grown a lot since then. But he purposely didn't show his full power. According to Shadow, the time has not come to start anything.
Shadow's real body is far away in the last room. The place where Lucifer Wit's Godstone is located. In that place with his own ability, he had even managed to release the object from the place that was holding him without triggering anything that harmed him.
Cunning, Shadow has shared this plan with Envy, Doc to Drazzel. The people that Shadow really trusted from a long time ago. The people who had been in his circle since he was still not as strong as now.
