The monster refuses to be dispatched!!! Stinkin' zombies just...won't...DIE!!!

Vesta's eyes go wide as she watches Zyl practically double in size. Now there's a trick that would be useful to learn! As the fairy takes a swing at the zombie that hit her, the sorcerer focuses another blast of fire at the zombie (purple) who missed her.

Fire Bolt Attack: 10 Damage: 9

As the zombies disperse from Dara, Celeste continues to fire off a barrage of arrows, trying to strategically pick them off based on what would be most efficient.

Action - Cast: Frostbite Con ST DC13 On a failed save, the target takes 1 cold damage, and it has disadvantage on the next weapon attack roll it makes before the end of its next turn.
BA - Luminous Arrow Attack: 12 Damage: 11 Radiant damage

Celeste continues the barrage of magically augmented arrows to help her fairy friend, trying to freeze the black one (DC13 Con save: 10 - if it fails - DC6 fortitude save: 4) and hitting the purple one.
Hollis seems to be hidden in the passage, avoiding combat...

2nd round: (black and purple remain. Yellow, blue, green and pink zombies turned)
Vesta manages to hit the purple zombie with her weakly thrown firebolt! (DC14 fortitude save: 23) 
Mulligan ???
Dara ???
Zyllyne gets swol and swings at the black zombie, but it refuses to be dispatched!
Zombies ...

(Red, lt blue, and black are now dead dead dead. Purple manages to stay up. Other four remain turned...updated map)

     "Look out below!" Mulligan calls out and throws more psionic blades, aiming at the (purple) one engaged with the great big faery...

Psychic Blade Attack:  24 to hit for 9 psychic damage
Bonus Action Attack:  21 to hit for 7 psychic damage

Dara steps further into the chamber, noticing Zyl and Mulligan locked in a struggle with a particularly stubborn zombie. He shifts his focus to the remaining zombies, raising his hand, fingers stretching towards the dark creature. With a murmur of prayer, he calls upon Eldath's light once more. 

Sacred Flame on the green zombie, DC 15 Dex save or 5 radiant 

2nd round (con't): (purple remains. Yellow, blue, green and pink zombies turned)
Vesta manages to hit the purple zombie with her weakly thrown firebolt! (DC14 fortitude save: 23) 
Mulligan throws more energy blades at the purple zombie (DC14 fortitude: 23 and if it succeeds the first one, DC12 Fortitude: 8)
Dara calls down flame-like radiance on the green zombie! (DC15 Dex save: 0)
Zyllyne gets swol and swings at the black zombie, but it refuses to be dispatched!
Zombies ...

2nd round (con't):
The purple zombie stays up and keeps swinging at Big Zyl! (Attack: 11 Damage: 9) The green zombie withers under the radiant damage...(no fortitude save!) Yellow remains turned - other two are nowhere to be seen.
Celeste
Hollis

3rd round:
Vesta
Mulligan
Dara
Zyllyne

Celeste will stare down the sight of her bow, prioritizing targeting the purple Zombie attacking Zyl. She fires off her pair of arrows. While her frosty arrow may feel like a snow flake on the tongue, the arrow that mattered the most, filled with radiant energy strikes the zombie through it’s skull.

Action - Cast: Frostbite Con ST DC13 On a failed save, the target takes 1 cold damage, and it has disadvantage on the next weapon attack roll it makes before the end of its next turn.
BA - Luminous Arrow Attack: Nat 20 for 25 Damage: 12 Radiant damage

     Mulligan, staying up on the ceiling and keeping his distance, one more summons and throws a couple psychic blades in defense of our favorite giant fairy...

Psychic Blade Attack:  17 to hit for 7 psychic damage
Bonus Action PsBlade:  16 to hit for 8 psychic damage...

While she can no longer see two of the zombies that fled from Dara's power, there is one zombie left that is still trying to get away (yellow). Vesta doesn't want to let any of the zombies get away. She doesn't want them attacking the group later so she flings another bolt of fire at this remaining zombie.

Fire Bolt Attack: 20 Damage: 5

2nd round (con't):
The purple zombie stays up and keeps swinging at Big Zyl! (Attack: 22 Damage: 7) The green zombie withers under the radiant damage...(no fortitude save!) Yellow remains turned - other two are nowhere to be seen.
Celeste hits the purple zombie with cold (DC 6 Fort save: 23) and if it doesn't fall, she nails it with a radiant arrow, ending its undeath!
Hollis  ???

3rd round: (only yellow left - blue and pink are gone...)
Vesta sends a fiery orb at the yellow zombie
Mulligan sees the near zombie go down, so turns his attention to the remaining undead monster in the chamber (yellow).
Dara ???
Zyllyne ???

Zyl howls at the slash from the icky zombie, starting to look like she's taking a beating, but once it's gone she stomps over to the last zombie and swings wildly in her rage!

To hit (reckless): 16; 13+2 (15 total) slashing damage (rolled in log)

Bonus Action: none

DC20 Fortitude: 16 - Combat over!

What was once a serene crypt now lies in ruin. Two chipped stone pillars brace the vaulted ceiling. Tombs are cracked open, and corpses lie about the room. At the center of the room’s back wall is a dirtied and desecrated shrine bearing the image of a blank scroll.
DC 10 Religion

Vesta goes quickly to Zyl. "Are you all right? Do you need healing?" she asks the fairy. After making sure that Zyl is going to be all right, the sorcerer examines the shrine. She has never been particularly devoted to any god, but she is relatively familiar with most of them. She recognizes this symbol as belonging to the god Oghma, god of knowledge. "I wonder what a shrine to Oghma is doing down here in this dank place," she comments.

Religion - 20

     Mulligan looks around with more psychic blades in his hands, ready for more... But sees no more.  "Weren't the more of those things?" he asks, not quite nervously but also not liking the idea of there being more lurking unseen.

     "Oh well, what've we got?" he asks, seemingly dismissing his concern in a blink and dropping from ceiling to floor to check out the old shrine.  (Religion Nat 20 for 21). "Oh! Oghma.  Well why not down here?  Not all knowledge is bright and cheery, now is it?"

Celeste nudges any body or bone near by with her foot to double check. Once satisfied that no more zombies were going to spring to life, she immediately goes into sniffing mode. Her nose huffs and puffs, snorts and contorts, leading her along an undead trail. She'd gag once or twice over the scent of decay and undeath, but she wouldn't skip a beat as she made her way over to meet Vesta at the shrine, to smell it of course. "If Oghma's here, then wouldn't that suggest knowledge?" She cranes her neck to sniff higher on the statue. "I wonder if there's some important stuff tucked away or being protected..." She muses out loud. "Can we fix it?" The druid was no stonemason or artisan, but she can provide guidance and adorn it with pretty flowers!

Religion: 20 (Rolled in log)
Perception: 7 (Trying to sniff out a trap or secret door/passage, perhaps forgetting to use her eyes)
Investigation: 16 (Looking for a hidden item or knowledge, now remembering to use her eyes. And maybe how they can fix it?)

Hesta, Celeste, and Mulligan determine that cleaning the shrine and doing something to honor the god will likely restore it. Since Oghma is the god of knowledge and patron to bards and wizards, then either a rousing performance or pouring some magical energy into it should appease Oghma.

Vesta studies the shrine along with Celeste. "Hmm, I am no wizard, but perhaps any touch of magic will do?" she thinks aloud. Then she reaches out and lightning arcs from her hand into the shrine, crackling and powerful.

Shocking Grasp - Attack: 22 Damage: 5