(Oh I thought we were in the same room!! sorry in that case and if is possible a retcon Kray wouldn't let the griffon to its own devices to attack whoever he wants! she will keep on melee with him.. 

In case it is possible: 

 Ii would edit my post to reflect this if we finally retcon. Sorry!
If not its perfectly ok!! ) 

(Lostur killed the griffon, no worries.. it's not attacking anybody anymore :) )

(Not a problem Kray. As Lostur says, he killed it) I will wave the damage from the AOO on account of the confusion. You are now in the library helping Lorvax)

Lorvax you start to struggle for breath as the rug wraps tighter around you. Take 10 damage as your turn begins.

You can roll with advantage to break free.

Lorvax movements become increasingly more frantic and desperate as he claws at the rug.

Strength Saving Throw (with Advantage): 8 8  ((2x 4's on a d20 - DnDB hates me))

Unfortunately, he is unable to break free from the object's grasp.

((Can Brenvull try and help unwrapping Lorvax (by rolling an own athletics(?) check?) Or does he think he can Toll the dead the carpet without hurting Lorvax?))

((Damn Lorvax that is rough;  DC 13 Strength to get him out Brenvull and that would be your turn. As to the spell effect roll an intelligence check))

Lorvax your chest is beginning to heave with the lack of air and the discomfort of approaching suffocation.

Brenvull will go to Lorvax and try to free him from the rug: "I cannot remember the rugs and tapestries attacking before!" 

Strength: 10

Brenvull you rush in an try to remove the rug, but try as you might it just seems to be squeezing tighter around you companion.

Lostur and Kray?

Kray grunts and tries to free Lorvax too from the rug, trying to rip it off. 

"You... let him... go..."  she says

(STR: 17 )

Lostur is only too delighted to get a chance to whack at a murderous carpet. 

Intelligence check: 7

He stops short, yklwa raised, wondering where Brenvull went, and what the lump in the carpet is.  He doesn't make the connection though, and follows through on his strike with a rebel yell.  "Woo hoo, let's turn this rug into thread!"

Yklwa: 11
Damage: 18

Yklwa: 28 (crit)
Damage: 26

Lucky for you Lorvax, Kray manages to pull the rug free before Lostur starts tearing into it. Lorvax you drop to your knees gasping for breath. 

Lostur your first attack missed as the rug is suddenly yanked to the side. However, your second attack makes up for the miss as you shred a great gash into the centre of the rug. It is looking in bad shape. The rug then whips toward your head Lostur Attack : 16

((Hit: The creature is grappled (escape DC 13). Until this grapple ends, the target is restrained, blinded, and at risk of suffocating, and the rug can't smother another target. In addition, at the start of each of the target's turns, the target takes 10 bludgeoning damage.))

Lorvax you are up!

R5

Lostur stares at the rug approaching in confusion, then simply rolls through the enormous gash he made, evading the fabric hug.

Lorvax gasps for breath, desperately trying to fill his lungs with air.  "Thanks," he mutters to Kray as he begins to stand.

Silently he makes his way towards the rug, halberd in hand, before he unleashes his anger towards the animated object.

Action - halberd attacks

• 1st Swing - Attack: 17, Damage: 8 Slashing + 2 Cold (Rite)
• 2nd Swing - Attack: 14, Damage: 14 Slashing + 3 Cold (Rite)

Bonus Action - Polearm Master

• Attack: 15, Damage: 7 Bludgeoning + 6 Cold (Rite)

"Damned, rug!  Take that.... and that... and that!" Lorvax's usually calm demeanour is washed away and replaced with pure anger as he attacks the construct.

The rug lies in tatters on the floor of the library and in the workshop the griffon has been returned to the tapestry. For the moment silence fills the air.

Would you like to explore either room further?

Lostur scratches his head.  "Uh...  wow, so you got eaten by a rug, huh?" he says to Lorvax.  "That's rough, man.  Anybody need some time before we go upstairs?" he asks. 

Lorvax gives the torn pieces of rug a final few stabs with the end of his halberd.  He turns to Lostur, breathing heavily and looking visibly worn out, "Even the damned furniture is against us in this damned place."

"Thanks for the assistance Kray," he says sheepishly.

"My pleasure brother" replies Kray "Do you need healing?" she asks.

"Well... That was something was it not?" Brenvull says as he carefully (perception: 13) goes around the rooms to make sure there isn't additional furniture ready to attack them and looking for stuff that might be helpful when going upstairs.

When he is done he replies to Lostur: "Ready when you are" and to Kray on healing: "I could help with that as well if necessary".

"Well, we can rest and heal up with some bandages and maybe save a few spells," Lostur suggests.  "I don't need healing, but I put all my magic in that fight.  Don't have anything left to give to anything waiting up there," he admits.  "Self control has never been my strong point."

Physically exhausted from the battle, Lorvax nods at Kray, "That would be much appreciated sister...  We can ill-afford to bide our time and rest here."