Onyx kneels next to the doll, inspecting it.  He doubted the spirit was gone, even if the doll was damaged.  Does he know of any rituals that might keep our from returning?

(Religion if applicable 15)

You’re not sure if the exact function of the doll. It seems lifeless and inert and while you don’t know if your suspicions of the doll are correct or not. 
So what do you know?  From earlier, you know it was certainly evil. You know it speaks a language you never heard before - similar in some way to abyssal but different. You take it as a bad sign. 
More powerful members of your order might be able to wash the evil from this doll but you’re not quite sure how to go about it.  Several possibilities come to mind - and that are within you and your party’s capabilities - but you’re not sure they’ll work....

Int check for Erven :  15 

Quote from Twombley >>

Int check for Erven :  15 

 Erven, you would venture to guess that this is likely Esme, the nursemaid. Looking closer, you see several dents, scratches, and notches on the bones. You’d guess hers was not a nice ending....

Bertolt moves to light a torch or to take one from whoever has one lit. With it in hand he will go over to the doll, attempting to burn the thing to ashes.

Erven turns to the others, "Another body to bury.  How sad.  Rest in Peace, Esme."  He looks over to the evil doll.  

"I have some holy water, would that be any help?"  He looks to see if there is firewood or kindling.  "Perhaps we can put it in the flames..."

Talion keeps his distance from creature that unnerved him so. "The only things one truly owns is your mind, your thoughts...your soul..." He stares at it in horror. It had tried to invade his mind, and he again thanks his patron for the strength to fight it off. It had been a close escape.

He sits on an uncovered seat, watching as the others complete the search. His eyes wander to the chest as Ervan pulls out the body and, needing something to do, he goes back out into the corridor and carries his chest back into the room. As he moves around, he glances curiously down the stairs to see if there is yet any sign of the mist.

Once the chest is in the room, he will assist anyone who needs it, but give the doll a wide berth.

The room fell eerie silent for a moment, as the gurgling sound of the broken doll came to a sudden stop. Sho watches as Onyx goes to kneel by the doll, his hand moves to resheath the shortsword back on his hip.

It didn’t feel like an animated object. More like a marionette. He thought to himself. A vessel. A host. He would chop it to pieces, scald it in fire, burn it to ashes, throw it out of the window, lost amongst the mist. Yet Onyx seemed to already have something in mind, and he felt it was appropriate for the one who killed it to handle it.

 ((Gonna wait to see if Bertolt"s fire has any effect.))

Bertolt puts the flames to the doll and it easily catches on fire. It burns for a time - hissing and popping-  scorched, and much of it is ashes. The charred remains lay at your feet....

no sign of mist.....yet....

Talion watches, the process from a distance, then remembers Lucky and tries find her and coax her out again with food.

"Whatever else you do with that thing, tie the remains with rope and lock it in the crate. Then...we should finish and move on. I don't like this room."

(( I assume we have finished investigating, per the rolls above? IIRC, there were some pieces of furniture yet to be uncovered. ))

Onyx removes the last sheet and a tall mirror stands before you....

Onyx turns from the mirror, back towards the doll, now that it has stopped burning.

"We picked up a flask of holy water, yeah?  Can I get one?"

If it is provided to him, he will carefully sprinkle the contents over the charred doll while praying to Lathandar that the spirit remains at bay for a few more hours.

As his panic recedes, Talion watches the others work on the doll, and starts to wonder what the creature was, how it attacked him, and how it might be destroyed or banished.

(( Does he have any prior knowledge or insight into this? ))

Erven turns to Onyx and hands him the vial of holy water that he has.  “Use it well my friend.  Let’s keep putting an end to the evil in this house.”

The flame goes up and then slowly goes out, leaving on the ground a pile of charred ashes. Sho watches as Onyx does his exorcism ritual. "Do you still sense it?" He feels safer to ask. He knows Onyx sensed something about the doll in the other doll, but not quite sure what it was.

Either way, he will cast protection from evil and good on Onyx before they open the door to the basement. 

Standing back up and moving towards the door, Onyx shakes his head.

"Most of what was in this house has been mindlessly evil.  That was different.  Intelligent.  It slipped away before only to recklessly attack here.  Fire and water, destruction and purity, hopefully have put it away for good."

He readies himself to open the next door whenever the party is prepared.

Erven bends down and pets Bear.  “I know now that you were called Lucky.  But I like Bear.  Will you come with us?”  He gives Bear a head scratch and a belly rub.  Then he takes up position behind Onyx and says “Ready.  lead on.  Let’s head downstairs.”

Bertolt hands the torch back, moving to kick the ashes of the doll so that it scatters about. "Shall we continue onward now? I do hope that we do not find anymore evil children toys..."

As the others move away from the charred doll, Talion uses a spectral hand to scoop up the pieces and drop them in the chest, and when all that remains is a burned smudge on the floor, he closes the lid. With the doll out of sight he moves forward and tries to lock the chest. (( Lock picks, if necessary/appropriate: 18 ))

When he has done what he can, he looks down at the skeleton, "Does not this one also need burial?"  He wraps the bones back in the sheet, again avoiding touching them, and hands the rolled up sheets to Bertolt, before taking his place by the door. "You seem to be the Keeper of the Bones". A flicker of a smile traces around mouth and makes it to his eyes, "Bones. I like that -- as good a nickname as any!"