The doors rip off their hinges. The sepulcher walls hum with arcane power. On stone shelves are leather cases, amulets, daggers, scroll tubes, unholy symbols, and other ornate objects. These are the phylacteries of Szass Tam’s lich servants.

They appear to be protected by some sort of arcane power.

DC 10 Intelligence (Arcana) check: ??!?!!?!?

Arcana:3

Arcana: 12

You figure out that disrupting the flow of eldritch energy within a sepulcher will disable the structure. Here's how:

Disrupting the energy flow requires intense concentration. It takes three successful DC 15 Intelligence (Arcana or Religion) checks performed by one of you who is proficient in that skill and is touching the target sepulcher. On each failed check, the character takes force damage equal to the amount by which the check failed. 

John Lee pops out of the Nether Realm that Characters go to when their players can't post to give these checks a shot.

Arcana:29
Arcana:20
Arcana:30

John Lee takes a bit of damage and tries again.

Arcana:29

Arcana:16

As JohnLee works to disable the arcane countermeasures from protecting the first group of phylacteries, fountains of shadowy energy burst from behind you near the levels center. A gleaming black humanoid skull flies out of the vortex. It has a ruby in each of its eye sockets and eight oversized glowing diamonds in place of teeth.

"Fools! It is inconceivable that you have made it this far! I shall destroy you all!" it says. You can tell by the music this is the end boss and guardian of the phylacteries.

Kazit Gul: 19
Taeli: 7

It’s the end of the world as we know it! 6

John Lee goes back to the Nether World.

Rosamia:14

MOMENTUM: 4, CHAOS: 31
Kazit Gul19(AC20/HP80), Rosamia14, Taeli7, Amelia6

Kit: 13

MOMENTUM: 4, CHAOS: 31
Kazit Gul19(AC20/HP80), Rosamia14, Kit13, Taeli7, Amelia6

Kazit Gul howls, emitting a bloodcurdling scream. Each creature within 30 feet of the demilich that can hear the howl must succeed on a DC 15 Constitution saving throw or drop to 0 hit points. That's right. Zero. On a successful save, the creature is frightened until the end of its next turn.

MOMENTUM: 4, CHAOS: 31
Kazit Gul19(AC20/HP80), Rosamia14, Kit13, Taeli7, Amelia6

Get ready Taeli: 23

(nvm) Amelia runs because she’s frightened!

Here we go: 8

Taeli drops.

Con: 20

Amelia does not run because I thought of another condition that makes you run away! Seeing Tae drop makes her heart drop, but she doesn’t have anything that can really help her in this situation. The fighter pushes on to try and attack the creature, hoping she hits him even though she’s scared shitless!

Attack: 22 Damage: 14
Attack: 17 Damage: 14
Attack: 12 Damage: 11 

Kit is a good range rogue, so there's no way she's within 30 ft, so she Hides and shoots.

Stealth: 26

Attack: 23 Damage: 44

MOMENTUM: 4, CHAOS: 31
Kazit Gul19(AC20/HP80), Rosamia14, Kit13, Taeli7(DOWN), Amelia6

Two of Amelia's attacks hit! Kit misses! As a legendary action, Kazit casts Energy Drain!

Each creature within 30 feet of the demilich must make a DC 15 Constitution saving throw. On a failed save, the creature’s hit point maximum is magically reduced by 11.

MOMENTUM: 4, CHAOS: 31
Kazit Gul19(AC20/HP57), Rosamia14, Kit13, Taeli7, Amelia6

MOMENTUM: 22

“Oh **** off!”

Conny: 22