[] Interrogate the spirit. Quietly so as not to interrupt Xuan Shi's conversation. Kongyou is obviously up to no good, you need to figure out what they're up to.
This seems like the sort of thing Kongyou aims to do as the sword kicking them out would cause a rift between Xuan Shi, and Ling Qi.
[] Don't let the nightmare bait you into conversation. Shush both Sixiang and Kongyou, and refuse to engage. Xuan Shi needs to focus on his conversation.
Now I'd expect this to poke Ling Qi's heart demon as it involves her shushing a member of her family over something they feel strongly about, and this ties back to Xuan Shi being correct that dreams can change, which is what has happened with Sixiang. Because Sixiang has previously commented they have some nightmare cousins, but despite doing so they have a "intense dislike" i.e hatred for Kongyou, and some of Ling Qi contemplation on family appears to have bled over to Sixiang as they do not consider Kongyou as a relative, which would be the notion of family being something you choose.
[X] Don't let the nightmare bait you into conversation. Shush both Sixiang and Kongyou, and refuse to engage. Xuan Shi needs to focus on his conversation.
Because Xuan Shi has chosen to bind Kongyou despite being aware of the risks, and this likely has to due with the nature of his parentage specifically his mother, which probably means it is part of his Truth, or at least what he wishes it to be.
Also this isn't the appropriate time for bringing up concerns given the sword told everyone to stop bickering, and I doubt Xuan Shi will listen regardless for the reasons pointed out above.