If the king was BD 99% of the time then in 99 out of every hundred games is an easy BD follows the king and wins. But what about the 1% of games? The chance of an EKing here is small enough that people don’t plan around it so it takes them off guard when it happens.
I’m not trying to say that King should only be evil 1% of the time. Just that the less likely something is to happen the better it is for scum when it does. The best things are when something that rarely happens can be deliberately triggered.
And that brings me to the observer who has 2 properties that are important here:
1 - Everyone agrees he is a terrible fake claim
2 - He doesn’t give feedback to his targets or anyone else
This makes him the perfect fake claim IF you can pull it off. This is because if you have enough information then people will belive you without question. This means that strategies involving getting lots of information that would normally not actually help you out too much now can give you an unshakeable fake claim that lets people give you the benefit of the doubt.
Without him or if there were too many classes that could fake him he would be just like the princess in terms of fake claim value.
The closest class to this is Hunter who gets screwed over in a CC but is relatively trusted if there is none.