"If you cast detect magic, can you check out the shield also?" Davis says.

Katarina will be able to sense any magic within 30ft of her for the duration (10 minutes, as long as she maintains concentration)

Davis attempts to see if the shield is magical just by inspection.

Arcana: 15

The shield does, in fact, have an aura of abjuration magic! But determining the exact magical nature of the shield requires an identify or spending a short rest examining and familiarizing yourself with the item.

There are no other magical auras (besides the items the characters have) within this chamber.

Once Katarina is able to discern that the shield does have a magic aura (assuming she shares that information), Vanizi says, "Great! We'll have to investigate it further when we get a chance. Now, do one of you guys want to carry it for now? Or do I just hang on to it even though I can't use it." She looks around at the group to see if anyone wishes to take the shield. "Now, what about this sarcophagus? Anything worth looking at there or do we just leave it?" 

"I checked the outside of the Sarcophagus, belongs to a respectable family, however I did not open it, nor care too, unless we think it leads us closer to the cult?"

Davis will then add, "I don't mind wielding the shield until we know more. But I'm good if another wants to."

Vanizi nods to Davis. "I don't imagine there will be anything in the sarcophagus to tell us about the cult. We should probably move on."  She hands over the magic shield to Davis, unless someone else lays claim to it.  She then starts to head over towards the exit to the west and stairs there, ready to follow the others. 

(Yes, Katarina did share her findings)

"Katarina is not entirely sure that she trusts the magic shield that was found in a place like this..." she says suspiciously. "So Davis, please take care with it until more we know."

"Will do" Davis says to Katarina. He ties his old shield to his pack and grabs the new shield. 

"Shall we keep moving?" he asks the group.

Heading out the western entrance and up the steps leading to the NW, the group emerges into a 35'x35' octagonal chamber. Glossy urns and cinerary boxes line the walls of this vaulted rotunda. Drifting in the center of the room above a drain is a ghostly, transparent, humanoid figure. The figure is clad in plate armor, and where a head should be, there is instead a featureless, luminescent orb. You realize that the armor the ghost is wearing matches one of the figures depicted in the sarcophagus’ relief carving from the previous room.

As you enter, the figure turns towards you and says in a sad-sounding voice, "Who am I? Do you know?" The ghost has no memory of its name or existence in life—a fact which pains it greatly... "Please...tell me who I am!" it beseeches you.
(updated map)

Halyqwyn looks around the octagonal chamber, also wondering about the magic of the shield as she does.  She is shocked as the figure turns towards them and talks to them.  Turning to the others, "Do we tell them about that family crest you found?" in a whisper.

Hearing Halyqwyn's suggestion, Vanizi turns to Davis. "You looked the closest at the sarcophagus. You think you could describe it to this ghost? Or does anyone know what family it might have been?" 

OOC: Sorry missed or didn’t get a notification.

Davis turns to the ghost and says “You are a member of the Hallwinter family. A noble family of renowned knights, known up and down the Sword Coast. Perhaps if you come to the room we just left, you will remember more and perhaps be able to rest.”

Davis will offer to escort the figure to the sarcophagus if they are interested.

Persuasion: 23 (nat 20)

"I...I think you are right. But what was my given name? Please - I need to know which one of the Hallwinters I was..." The ghost continues to float above the grate, not threatening you at all.

Davis looks at the others, "Perhaps you should return to the sarcophagus and search for a name? I may have missed it in my investigation. I will stay here with..." he looks at the figure in front of him "our friend, keep them company."

"I guess I can take a look Davis."  Vanizi starts to move quickly back towards the room with the sarcophagus. "Anyone to come with?"  Whether or not someone comes, she goes ahead until she gets back to the room.  Once there she steps up to the stone box, looking around for any indication of a name. (Investigation: 10)

Vanizi sees the same thing Davis did.  Engraved on the lid of the sarcophagus is a coat of arms depicting a blunted six-point crown, the crest of the Hallwinter family, whose lineage produced renowned knights throughout the Sword Coast. One of the figures depicted in the sarcophagus’s relief carving wears armor that matches the armor of the ghost you encountered. Perhaps there are other clues to be found elsewhere...

Halyqwyn follows Vanizi and starts looking around the area while her friend checks out the sarcophagus.  She was not upset about leaving the ghost behind, what a strange thing to see.

Perception: 20

Katarina, unfortunately, does not feel like she has a lot to do in this situation. So she'll provide the Help action to anyone who wants to search for clues to the undead knight's name.