(I am going to assume that Rhayna will have to be careful with her steps :-)

(It was meant to be on the opposite end so only if Gorlak runs and she chases him. I debated this a lot, but decided to go for it.)

Kaylyn is unsure that her blasts of energy are capable of knocking someone out, but they are very forceful, so perhaps.  With Pensive switching his mental emotions to Gorlak to help Kaylyn she sends a blast of energy up at him.

Attack: 20 Damage: 12

ROUND 5 cont...

With Pax laying a makeshift invisibility-detection trap and guarding the entrance, and Zeno attempting to draw Gorlak into a trap of his own, Rhayna remains alone on the bridge in the darkness with Gorlak. Also in the darkness but below the bridge, Kaylyn can hear the footsteps, grunts and groans, whip cracks, the whoosing and humming of blades and the creaking of the bridge above her. With the mental link of Pensive as a guide for herself and a distraction for the enemy, Kaylyn lines up another blast of energy and releases. It strikes true yet again. Apparently the mental yammering of the psuedodragon has made the difference, and Gorlak's concentration on the spell of darkness finally gives way. The bridge is revealed, along with the whip-wielding cleric, the warlock and her familiar, the blood-stained rogue, and in the centre, the over-sized, black-cloaked, duergar with the energy-sword.

Kastix's action to go, then I'll post Gorlak's action and update the map.

Kastix just fire bolts him without a care, "We're leaving after this. No if and or buts,"

Attack: 19 Damage: 2

its over 10! now if damage wasn't so low. 

ROUND 5-6

Kastix rounds the mesa as the sphere of darkness vanishes and the combatants are revealed, and he manages to fire off a bolt of fire at the enlarged duergar. Rhayna seems a little distracted by the sight of the oversized dwarf, and again can't quite get her whip to strike in the right place. Gorlak seems a little too wise to rise to Zeno's taunt, and instead turns around to finish off the whip-cracking cleric, but Rhayna finds dodging him easier than expected after having already done it in blind darkness.

Everyone can go again.
I've used BlueBayou's post #2687 to add a 30' move at the end of Sekkar's turn in Round 5 (after killing the last duergar).

map in progress - might not get to it for a few hours...

Pax, seeing the opponent revealed moves purposely in that direction, unleashing a bolt of magic, shadows leaking up her legs and into her fist to be released as a blast. 

Eldritch Blast Attack: 8 Damage: 3

With Gorlak now revealed, Zeno slips down the stairs and around the corner and attempts to Hide, pulling out his hand crossbow and firing again.

Stealth: 13 (dang.)

He’s not able to find anywhere with cover however, so he’s pretty sure the Duergar knows exactly where he is.

Attack: 15 Damage: 11

Sneak Attack (with Rhayna adjacent): 8

(LOL. Rhayna is dodge tanking now?? Going to wait for everyone to go first.)

(Without the map not sure where Sekkar is)

Let me know if you expected your character to be elsewhere.

The brown squares are Zeno's ball-bearings

"You're just getting annoying now!" Kastix fires another Fire Bolt at the big small guy.

Attack: 23 Damage: 5  

(Looks correct to me)

The target was way too far - if not for the Mark (moving Hunter's Mark at Gorlak), then for anything with "range" in it's description. Still, Sekkar tried to get his never-happened killer:

Crossbow: Attack: 5 Damage: 8  + 2 if hits by some miracle.

With the darkness removed Kaylyn glances around and seeing Zeno's injuries she sends a burst of light towards him (BA - Healing Light) for 10.

As Pensive continues his help by messing with Gorlak's emotions Kaylyn sends another bolt of power at Gorlak trying to knock him out.

Eldritch Blast Attack: 16 Damage: 11

If the large duegar is still up. She will try to definitely wrap her whip around him.

Attack: 14 Damage: 7

ROUND 6-7

Now exposed and with the group converging, Gorlak takes the full brunt of their attacks, being hit with energy blasts, fire bolts, crossbow bolts and Rhayna's whip. Kaylyn also speaks a word of healing at Zeno, but promptly vanishes from sight! With his endurance failing, and without the protection of darkness and the support of allies, Gorlak looks desperate and suddenly determined to cut with way through to the obelisk. Looming over Rhayna, with a few vicious slashes of his energy blade, the cleric falls before him, and he runs past her fallen form to place his hands on the obelisk...

Kaylyn only:

Kastix: edit your page and I can include your attack Updated
Sekkar: Yes, he can move close enough to be in normal range for hand crossbow.
Rhayna: I don't think there are any specific rules for grappling with whips, and in any case Gorlak was already adjacent, wouldn't have been prevented from attacking, and by the time he knocked Rhayna unconscious any grapple would have ended.
Kaylyn: won't take part in the combat this round I'm afraid.

(Ugh!! Spoke too soon. Since it was a hit, does a whip wrapped around the enemy helps Rhayna in any way?)

Pax sheaths her sword, running for the cliff to clamber up directly to the stone. On her way she absently let’s a glowing light emerge like a halo around her head briefly. 

(Healing light on Rahyna for 4 hps.)

Zeno yells out "Nooo!!!" as Rhayna falls under Gorlak's blades.  He rushes up the stairs and across the bridge, quickly and carefully picking his way through the ball bearings he had left behind when the darkness was still around them.  He stows the crossbow, drawing the rapier again, and leaps at Gorlak.

BA: Dash

Attack: 13 Damage: 6

(If this brings Gorlak to 0)

Kastix lets out a tried sigh before he moves toward Kaylyn and if he can reach her with regular movement, cast Cure Wounds to bloster up her hp. Dash if he can't make it this turn.

Cure Wound: 13