Realizing Raqisat simply goes ahead and shares blood anyway, Aubrey would see no point in messaging him, and possibly that is how he would prefer it.

     Raqisat clasps the other by the shoulder as they shake as well.  "Welcome, brother.  Through the bond of blood may we swear to always have one another's back when needed," Raqisat responds, hoping it suits the occasion. 

     Raqisat will look to Cosette and give her a smile and a small shrug as if to see "All good.  No big deal."  He knows the party wanted these people as allies and friends and his past warned him that rebuffing such an overture could quickly turn bad.  Deeper concerns about these people and their closeness to rats did not occur...  Cosette had indeed brought it up as odd but they had not gone further down that road than that. ((I think?))

     Wrapping his hand up once Elton is also doing so, Raqisat feels he has cemented their relationship here.  They may not be full allies in all the groups pursuits but he believes this ceremony may have assured they have a place to rest and fall back to when needed.  

Would Rohuzar know anything about the dangers of sharing blood with creepy tunnel people?

Raqisat was his own independent man. If he wanted to go about making blood pacts with these people, Cosette wasn’t going to be one to stop him. He was the people person, not her. Sure she was an entertainer, but she didn’t study them in the same way he did. She’d return his shrug. Whatever cautions she had were tossed to the wind, left to be forgotten. 

Grugga nods silently after hearing Aubrey's voice in his head. Whatever concerns he has, he will voice later. For the moment, he pats Raqisat on the back. "Speaking of the king, shall we all head back and deliver this?"

DM, would Gel-Nagev teach about bloodborne diseases? Not necessarily lycanthropy (or whatever you call the rat version).

((Is Lycanthropy even bloodborne in D&D?  I mean our modern thinking would assume so by isn't it classically just transferred via bite or sometimes claw?  Even if they are Weres, they didn't injure Raq...))

Rohuzar:

I'd say that's probably a roleplaying question for you.  Growing up in the disputed lands, bands of fighters and militias had all sorts of 'bonding' rituals and a blood bond is probably something he would be familiar with.  But as to whether he finds it unwholesome in general, or unwholesome when it involves insular sewer people, that's probably for you to decide.

Grugga:

Gel-Nagev has been pushing germ theory, but even among his most ardent disciples it has been a difficult concept to grasp.  That said, as evidenced by the quarantines on Way Isle, it is well understood that diseases are communicable and exchange of fluids is one of the vectors.  Now... is Grugga squeamish about this?  That's entirely up to you.

Raqisat:

Good questions.  Good questions.

DM: I'm asking about cultural norms and learning in the world you built. Would a legion scout such as rohuzar know anything about exchanging blood as a danger or harmless ritual? Is this something where regular folks just have to guess? 

Rohuzar:  The ritual, in most cases, would be seen as harmless (from a physical sense) but serious (from a social/commitment sense).  The symbolism is that you are co-mingling blood with another; becoming family, in a sense.  This would not be done lightly.

However - there are stigmas around the diseased and the unclean.  Separate from the issue of blood bonding, there would probably be unease around sharing a bed, a toothbrush, or utensils with someone who lived in a sewer.  Not necessarily for fear you might catch something, exactly, so much as a more primitive idea that the person is unclean, and you might become unclean in the process.  And this could be a backdoor way into the idea of a blood bond with such folk also having stigma attached.

I'm trying to answer the question as I understand it and how Rohuzar might understand it.  Are we getting closer to the answer you are looking for?

Grugga will consider what Gel-Nagev has taught his people on the way to see the king.

The sewer folk send three down the ladder to collect the remains of the Death Kiss.

Once that's complete, those three follow along behind carrying the remains while Elton and another walk with you back through the tunnels in the direction of the main entrance chamber.

     "It is no doubt that your people had trouble with the creature," Raqisat says conversationally as the group walks through the tunnels.  "Such a strange and fearsome creature I have never encountered before.  It could lash out with it's tentacles dozens of feet and each had the strength of a dozen angry dwarves!  Out of it's eye it shot some kind of magical beam that could knock a fat Goliath through the air and clear across a ballroom.  And it's speed?  The way it zipped back and forth, it was like that pesky buzzy fly you can never quite swat...  It would only through the bravery and daring of my fellows that we were able to get the best of it.  There were times I was sure it would be the death of us all..."

     Raqisat is no wordsmith or master of stories so it is quite clear his tale is full of exaggerations and bravado. That's not the point though.  This isn't a full and factual report, he is not trying to deceive or convince...  He's just a fighter telling a tall tale to pass the time.  

Smiling to Raqisat's slightly embellished recount of their encounter with the tentacled aberration, Aubrey has nothing to add to that at the moment. "We are of course all honoured by your offer of sharing your blood Elton, but as previously mentioned I have an allegiance to my Emperor and I would need to know what is expected of me if I decide join your family?" The young noble asks in a very polite tone.

Grugga adds on to Raqisat's story. "Oh yes, the battle was quite something! We snuck up on the monster as it dwelt in its lair. We could have ambushed it in the room it had chosen to live in, but we knew that we needed to confine it to dull its strengths. Cosette lured it out of its den with a song meant to call beasts. We lured it right into a dry, narrow hallway to put it at the greatest disadvantage and then we all attacked!" He leaves room for others to take over the story if others wish.

While the group is telling its story, he listens for the answer to Aubrey's question with interest.

As the group continues to walk, Elton addresses Aubrey.

"I have no doubt something can be arranged to make use of your connections within the remnants of the old Empire.  I can see how that could come in handy, especially if they do somehow succeed in retaking the upper city within our lifetimes."  He calls a halt, then stops and turns to look at all of you.

"To be clear... all allegiances, present or future, are secondary.  Our holdings, our treasures, our secrets... these will be yours too.  But any connections you maintain with the world outside can only be in the context of working as agents of our society."

"That is the way it must be."

"Well, although we are all of course honoured by your generous offer to join your family I hope you can see Elton that this is a step that will profoundly change our lives. I believe some of us might need a moment to think this through as our new commitment will have consequences for other plans we might have had, plans that now must be altered." Aubrey says in a polite tone.

     "The two groups are linked through me," Raqisat declares loudly and with confidence.  "Surely the rest can be worked out between The King and Aubrey in due course, yes?"  

     With that said Raqisat clasps Elton on the shoulder and walks next to him.  "Brother...  Of course they have some hesitancy.  Most of them have spent way too much time in the land of laws and society and snobbery.  I'm sure The King will win them over in time.  Leave it to him.  Us?  We can relax and just enjoy life..."

Elton listens to Aubrey's response, then Raqisat's interjection.

He turns to look at Grugga, Leelan, Cosette and Rohuzar.  "And what of the four of you?  Are you also worried about how this arrangement might upset your plans?"

Rohuzar shrugs. "Ve came for a reason, not to join yours. This thing you say is... Sudden. Happy to be allies, friends. But you ask too much. You are not so removed as to think ve could accept your offer. You offer responsibility but no reward. Afterall, ve could not take the treasure and leave vith it, eh?"

Leelan readjusts his glasses. "With all due respect, we’re very grateful for your help and hospitality. But we may have had…some unfortunate misunderstanding. Given what we know of this city, it’s better to have friends than foes. Our service to you was in the hopes of showing our good faith and avoid unnecessary hostilities."