Hadrian misses and as Elyse's wounds close, so do the Spawn's as it decides to change tactics and just take Elyse down with its claws, so that he can feast on her blood. 

Attack: 14 Damage: 8

Attack: 22 Damage: 9

Fae now moves 80 feet closer.

Enialis dashes with his sister. Elyse and Hadrian are up.

Elyse reluctantly uses her action to take a moment and use her remaining 11 points from her Lay on Hands pool on herself. 

Hadrian keeps the ghostly hand grasping at the vampire thing, desperate to keep it from regenerating further. Fear is plain on his face. 

Chill Touch Attack: 13 Damage: 4

Hadrian misses as his desperation begins to negatively affect his aim. As Elyse heals herself, so does the vampire, who now lashes out at both of you, looking like it's almost completely recovered from your earlier onslaught.

Claw on Hadrian

Attack: 12 Damage: 5

Claw on Elyse

Attack: 25 Damage: 7

Disadvantage on Hadrian

11

Also, at this point Fae and Enialis have dashed down to you. They'll be able to attack in the next round, after Hadrian, Elyse and the spawn.

Hadrian and Elyse are up.

(wow Hadrian's rolls in this fight are as bad as the Spawn trying to bite Elyse)

With the silvered shortsword now in hand, Elyse's eyes flash with anger as she lashes out again at the Spawn. 

Attack: 15 Advantage: 23 Damage: 9

As she sees Fae and Enialis arrive, she yells out "Stay out of this Fae, this is not your fight!"

(the vampire should have disadvantage on attacks against Hadrian, thanks to the protection spell)

Now engaged with the vampire, Hadrian calls forth the toll of death... 

WIS Save DC 14 or 1 necrotic damage

(Re-rolled for disadvantage above, but I'll remember to put it in next time)

Wisdom Save: 6

The vampire hears the bells of death and feels the sting of the blade, but it is still able to resist the attacks and heals the damage that was dealt to it.

It once again moves to claw at Elyse and Hadrian

Hadrian

Attack: 7 Damage: 5

Elyse

 Attack: 13 Damage: 7

Enialis and Fae are up

(lol wow, he hits me with his first attack, meanwhile I'm rolling miss after miss... fat lot of good that spell did! Here's the concentration check 9)

...kill me now...

Fae skids to a stop upon seeing the not so great situation unfolding, and frowns. She races up next to Elyse and Hadrian. "Will you go and leave him alone now?"

She will also Ready an action to attack with her quarterstaff if the spawn attacks.

Readied Attack Because I'm About to Go AFK for a Bit:

Attack: 18 Damage: 6

Enialis begins to work some magic as he says "Come on man, we're old friends. You don't need to do this." (DC 12 Wis ST against Charm Person) 

Fae makes her heartfelt plea to her comrades, ready to strike at the spawn if it attacks. Enialis' spell fails, the altered mind of the spawn protecting it from the spell.

Hadrian and Elyse are up.

Hadrian disengages and backs away from vampire. "We cannot overcome this inhuman monster! It heals its wounds as fast as they are made; even silver is no use!"

(Would it be a full action or a bonus action to switch back to the glaive?)

(Did you drop the glaive or stow it when you took the shortsword? I assumed that you dropped it, because stowing it would be an action)

You can take the glaive as a bonus.

After discarding the shortsword and picking up her trusty glaive, Elyse shouts "Don't give up so fast Hadrian!" as she swings the weapon down at the creature once more. (Still at advantage for 2 more turns)

Attack: 18 Advantage: 11 Damage: 9

Elyse's strike connects, but it regenerates the damage, like it never happened. Seeing that there's too many of you to take on at once, even if there's reluctance, it disengages and retreats back to the corner, hissing at you as it does so.

Hadrian, holding his side in pain, picks up the silver shortsword and gestures towards the door. "I see no way of overcoming the evil in this creature. It is simply too strong for us."