The Tales of the Fellowship of the White Cloaks

“You make a valid point about not touching the Mythallar, Rhogar,” Krom says with a nod. “In its damaged state, it may not be the wisest course, at least not unless we run out of other options.”
The dwarf scratches his chin, then flashes the group a toothy grin. “We’ve slain dragons and brought down an undead Netherese archmage. I’m sure we’ll find a way to put that goddess back in her place without having to summon that monster.”

Rhogar gave Chill a shrewd look; but, before he can say more, Kazri's concerns prompts the dragonborn to raise his hands in surrender and nervously chuckle. At least he would raise his hands if both weren't occupied by two different staffs. But after an awkward moment of stashing the staff of power into his bag of holding for the time being, he'd go on to assure Kazri more thought would be put into releasing the monstrosity before anything comes of it, and even makes promises to work on the scrolls destruction after the goddess was dealt with, if but to ensure it never fell into the wrong hands...

"Mm? Mn... That we will, Krom. Now, if we're all ready... *ahem*...Saldrinar!" The dragonborn commands before waiting with baited breath for the doorway to appear. When it does so, the dragonborn breathes a sigh of relief, and after nonchalantly motioning for the others to go ahead through, he follows them out.

If when all said and done nothing untoward awaited the party on the otherside, Rhogar follows the others back to Oli. There he waits for whoever wishes, to 'talk' to Oli and mentally prepare him, before Rhogar twinned cast his blessings of flight upon both Oli and Kazri(just in case).

The plan is set, fetch Oli so he isn't alone and bring him with you to the study, a seemingly safe place to rest and get ready for what is next.

Rhogar speaks the word and the door reopens and you quickly step back into the Chamber of the Ebon Star.  Back down the darkened hallways.  You don't know their secrets, but you know enough to avoid trouble and the darkness does not daunt you.  You return to the shaft and look down to see Oli there, waiting with Gorrah.  All is well, which you know if things and had changed Gorrah would have alerted Rhogar as soon as it had.

Chill can quickly slip down a rope and speak to Oli.  Oli is very uncertain of what to do. 

Rhogar calls upon the power his patron has given him and gives both Kazri and Oli the ability to fly.  Kazri can descend the shaft and speak with Oli herself.  

Kazri, make an Animal Handling handling skill check with advantage.  

Kazri Animal Handling (adv): 14

(WOW)

Kazri tries to explain to Oli the situation, but it seems that he is not budging.

Kazri tries to coax Oli and explain how the flying worked.  Even Chill close by and giving help just wasn't enough.  Oli can't figure out how the flying works and becomes nervous and angry about this change in his life.  

In the end Oli refuses to try and fly up the shaft.

Kazri would not abandon Oli. "I shall remain here with Oli." She signals to her companions to go back to the chamber. "Please get some rest."

“We cannot do that, lass,” Krom replies firmly, shaking his head. “We must stay together, and you need rest as well. You know the final stretch of our quest, the most dangerous and critical part, lies ahead.”
The dwarf pulls a coil of rope, a set of pulleys threaded with an iron cable, and a hauling hook from his backpack. He spends a few moments assembling the contraption, then secures a loop of rope around his waist before casting the hooked end toward Kazri. “Tie it to Oli, I’ll haul him up, since he doesn’t care for flying.”
Krom then turns to Rhogar and Chill. “I may need your help pulling him up.”

Chill did his best to try and help Oli but in the end it didn't work.

"Whatever you need Krom, I'll help."

"Mn. Well said, and well spoken Krom." Rhogar said with a bit of chuckle behind his voice. Meanwhile, Gorrah sends Kazri images of the group hugging each other and looking oddly more buff, and then image of Kazri alone against many shapeless shadow monsters and looking worse for ware. "I'll be right up. Gorrah, why don't, uhh, stay down here for a little longer and keep'em company, yes?" The dragonborn requested of the familiar.

To which, she feigns reluctance in a cheeky sigh, before flying over to roost on Kazri's shoulders. Rhogar chuckles as he ascends on the previous rope chain the group had assembled, joining Krom and Chill by the dwarf's curious contraption. "Here's hoping this work. For if not, we might just have to chance sleeping out in the proverbial elements and hoping for the best." He says to Chill and Krom once he's back at the top. 

Where there is a will there is a way.  Krom set up his block and tackle.  With Kazri soothing Oli the line is looped around him.  The combined strength of Rhogar and Krom is enough.  While young owlbear weighs several hundred pounds the dwarf and dragonborn are able to lift him up.

Once you are all on the same level you can easily return to the to sanctuary of the demilich's study and rest.

You may long rest

Oli still a little scared, is afraid of the rope. "Allow me Master Krom." Kazri gently wraps Oli, as Gorrah tries to soothe the Owlbear. She remembers that not long ago he was just a small cub, and now he is all grown up. "It will be ok." She reassures him, and slowly the group is able to get Oli up, and finally to the chamber. She stays with Oli for the whole time they are resting. After some time, the Owlbear finally falls asleep. "Thank you all for helping to bring Oli here."

"By Moradin's beard, you're heavy, Oli!" Krom grunts as he hauls the owlbear up with the help of Rhogar and Chill. Beads of sweat form on the dwarf's brow as he strains against the weight.
Once safely inside the demilich's study, Krom retrieves the four vials of quicksilver from his backpack and begins another hymn of identification.
"They may prove useful." The dwarf remarks to the group.
After completing the ritual and sharing his findings with the Fellowship, Krom checks his gear, making minor field repairs where needed before finally settling down to rest for the night.

The next morning, after offering his prayers to renew the All-Father's blessings and donning his armour, Krom addresses the group.
"This is it my friends. I can feel it, we stand at the threshold of the end of our long quest." The dwarf flashes shows a toothy grin, "Let's put that goddess back in her place!"

As exhausting as it might've been to haul up an owlbear, the act left Rhogar more amused to the point of laughing in-between breaths. But with what felt like the final battles on the horizon, Rhogar later retrieved the Staff of Power from his bag of holding to attune to it over the course of the rest. But afterwards, he sees it returned to its confines, as the group still needed to make their way down the strut at some point. Not that traversing the strut itself necessitated such caution; but, on off chance a certain brain in a jar decided to roam, having the key to the restoration of her people out in the open might've made things... awkward, to say the least.

Regardless, that 'morning' the dragonborn spared no spices or sides to ensure the party had a hearty breakfast awaiting them, and a few snacks in the form of trail mix bars for later besides. "I couldn't agree more, Krom. And if everyone is ready, let's say the words to lower the barrier and be quick about things, yea?"

Krom is able to identify the small metal case containing four vials of quicksilver.  There are no magical properties to the quicksilver.

Your long rest passes by without incident.  But you can't hide in the spire forever...

Krom nods at Rhogar and places a firm hand on the handle of his warhammer.
“I’m as ready as I’ll ever be, Rhogar. Bring down the barrier around the Spire.”

After a good breakfast and feeling well rested, Kazri is ready whatever comes their way.

"I'm ready." Chill says when his gear is stowed and he breaks his fast.  

"Where to now?"

Rhogar nods to Krom, but Chill he just gives a half-smile and says, "To the Mythallar, of course." With that, he then clears his throat, and pulls out a scrap a paper: a cheat sheet of sorts of penned down important names and then some.  In calling out "Saldrinar,” he'd once again reopen the space between the study and the rest of Ythryn. A needless precaution perhaps in the end, but one he'd follow up with motioning for the fellowship to make for the exit as he read out "Olostin", dismissing the barrier around their next destination. 

Permanently. Both dragonborn and psuedodragon sharing a look as the thought hits them. But then with little more than a grunt of discomfort, the pair take off after the others and join them outside. From there, it was supposed to be a simple matter of getting Oli back down the shaft, maneuver across a certain invisible bridge, and take the magical lift back down the strut, as no other passage they'd discovered thus far seemed to link to the area beyond the barrier. Still, Rhogar went on to carry himself expecting the proverbial other 'shoe' to drop at any point during the journey.

You make your way out of the spire. Getting Oli back down the shaft is simple enough for Krom to manage with his block and tackle.  You all get down the shaft, maneuver across the invisible bridge, and straight out of the spire to take the magical lift back down the strut.  Rhogar is wary the whole time but the deed is done without any unexpected events occurring.  With the field down you can then access the area beneath the spire where the Mythallar sits.

Beneath the great spire, a luminous fifty-foot-diameter crystal sphere rests on an ornate stand. The mythallar looks like an enormous crystal ball held in an ornate cradle. The globe sheds bright light in a 300-foot radius and dim light for an additional 300 feet.