"According to my research, this door should be opened with a key. Once you get the key, you can easily push it open." Negris managed to say with a straight face.
This should be a door similar to those opened by magic markings, requiring some sort of verification, and this method of verification is the key. Unfortunately, who knows what kind of verification it uses?
So, it's not his fault if the door can't be opened. What others use for the key is beyond the scope of 'Knowledge'.
In fact, Negris had regretted it long ago. When he boasted in the past, he used a term called 'Omniscient', which was just a slogan to fool believers. That's because those who believe in the God of Knowledge would never ask such inexplicable common-sense questions.
So when he saw Ange as Little Skeleton, he merely went along with it and ended up falling into a trap.
