The Dukes didn't look at the blade in the same way Han Sen had. They all looked at it for less than a minute before handing it back over to Black-Moon King. The entire thing was done in a few minutes.
The young ones were not allowed to look at it by themselves. After they had all seen it, the ceremony came to a close. Black-Moon King invited a few Kings and Dukes over for tea. Some accepted and stayed, others declined and left.
Black Steel invited Rebecca and a few of the other young ones to the garden for a chat, Han Sen included.
So, Han Sen followed Black Steel to the garden. There, he sat down. Aside from Han Sen, everyone seemed to be acquainted with one another. So, there was no formal etiquette to follow.