(It’s impossible for me to get below 4, so 9 )

Baik stands back as well, accompanying Corvins own Sacred Flame with his own burst of Golden Rain . 

( 13 Radiant Damage on a failed dc 16 Dex save)

Eiren will use his second wind right after the last battle, 9 healed

Eiren initiative: 10

Eiren springs into action and, quick as lightning, enacts a bladesong and begins slicing through the Wight with his magic rapier (moving to D9 and attacking. If the Wight is dead, he will engage the Dread Warrior at C10 and attack that one instead). 

Attack: 27 Damage: 7 piercing
Attack: 21 Damage: 14 piercing

(If either of the attacks are redirected at the prone Dread Warrior, here is the advantaged attack roll for the second attack, with the delicious Elven Accuracy option to dump the lowest of two d20s and roll it again!...)

Conditional attack 25

Jeez and the advantaged additional damage... +3 piercing

Velmine does a crazy roguish maneuver, that let's her move into melee range attack the Wight and get out of his reach. Her rapier strikes true, but without magic, the strike in not quite as deadly as her normal attacks.

Wight Dex save 1 (Corvin) 18

Wight Dex save 2 (Baik) 12

Both Corvin and Baik cast Sacred Flames. The Wight dodges Corvin Sacred Flame,  but moves directly into the path of Baik's Holy Fire. 

Eiren moves to D9 and finishes off the Wight. He then moves to C10 and attacks the Dread Warrior, doing considerable damage. 

(Velmine you can see the Dread Warrior. Xavier, Corvin, and Baik can see Eiren attacking something that they can't see. )

Xavier roll initiative and act if you roll high enough. 

13 initiative

Xabier will move up to G11 and attack the dread warrior with a fire bolt 

Attack: 13 Damage: 8

Roll for disadvantage due to prone 16

Xavier moves to where he can see what Eiren is attacking, and seeing the Dread Warrior cast a fire bolt. The fire bolt hurls over the prone warrior and lands sizzling in the pool.

The Dread Warrior grabs his discarded Battleaxe and stands up. He makes two attacks against Eiren with the Battleaxe in both hands. The first Attack: 10 Damage: 7 fails to connect with Eiren armor, let alone do any damage. The second Attack: 14 Damage: 4 is caught up in Eiren's Bladesong. 

 Back to the party 

Seeing the fight is going well, Corvin simply fires off another Sacred Flame, conserving his more powerful magics.

DC17 dex or 4 Radiant damage.

Eiren faces off against the ugly undead and attacks again...

Attack: 21 Damage: 14 piercing

Attack: 16 Damage: 8 piercing

Corvin moves to H11 (to where he can see the Dread Warrior) and casts Sacred Flame.

Dread Warrior Dex save 10, the Dread Warrior in engulfed in radiant fire.

Eiren attacks the Dread Warrior with two jabs with his rapier. The first strikes the undead creature, while the second misses. 

Xavier, Velmine, and Baik are up 

Velmine dashes behind the tree next to Eiren, going always close to the wall and away from the tree itself. She finally stops very close to the warrior (B11), where her rapier skills are displayed one more time.

Attack: 15 Damage: 22 Piercing

She then makes her way back out to B13.

Baik himself maneuvers around Corvin to H12, to see what everyone’s stabbing at. Upon spotting the Dread Warrior from there, he joins Corvin once more in a blast of Holy Fire to vanquish this foe.

(DC 16 Dex or 11 radiant damage)

Velmine moves to attack the Dread Warrior. Her rapier just manages to find a weak spot in it armor. 

Dread Warrior Con save 8

The rapier hit a vital undead organ, because the Dread Warrior is now dead

Everyone receives 180 xp

Time in the Doomvault: 0 Days 14 Hours 3 Minute

Baik (25/77) - 0/1 Saving Face, 0/2 rages, 2d6/9d6 healing light, 0/1 tomb of levistus, and 1/2 fourth level spells. Hit Dice 5/8 Warlock, 0/1 Barbarian. 

Corvin (54/66) - 1/4 first level spells, 3/3 second level spell, 1/3 third level spells, 0/3 fourth level spells, 0/1 fifth level spells. 0/5 Embodiment of the Law, 0/2 Channel Divinity. Hit Dice 3/9.

Eiren (60/63) - 2/2 Bladesong, 1/1 Second Wind  0/1 Action Surge, 4/4 first level spells, 1/3 second level spells, 0/1 Blessing of the Raven Queen, 1/1 Arcana Recovery. Arrows 30 remaining (out of 40). Hit Dice: 3/7 Fighter, 2/2 Wizard. 

Velmine (44/57) -Martial Adept 0/1. Bag of Tricks 2/3, Hellish Rebuke 0/1, Darkness 0/1. Hit Dice 3/9 - [Animal Hit Points: [Mastiff: 3/3]

Xavier (42/65) -3/4 first level spells, 2/3 second level spells, 3/3 third level spells. 2/3 fourth level spells. 0/1 fifth level spells. 3/9 Sorcery Points, Healing Hands 0/1, Necrotic Shroud 0/1. Hit Dice 6/9.

Do you stop to search the bodies or continue straight away towards your goal of The Golem Laboratories?

If you don't stop Eiren will have 3 rounds left of his Bladesong as you exit the White Gate. 

Eiren will search the grisly undead bodies, starting with the dread warrior and then moving to the wight.

Eiren decides to search the undead bodies. First he checks out the Dread Warrior, but don't find anything interesting. Next he searches the body of the Wight, in a pocket he find a Glyph Key attuned to the Iron Golem Foundries (where you are heading.) Whether or not Velmine is comfortable with the Golem Laboratories, it looks like that is where you are going next.

 Eiren then leads the party to the White Gate leading to the Iron Golem Foundries. As Corvin enters the other side of the gate he sees a short hallway ending in a bigger room. Determining that there is enough room in the hallway, he decides to wait until Eiren is through to set up the normal marching order. 

After a few seconds the whole party is through the gate and you are ready to proceed. With Eiren at the head once more you venture forward and see...

...A largish hall like room. At the center of this fiery hall is a huge crucible that emits vapors. Dozens of molds and piles of armor plate, and large Falchions are spread out before six hulking armored figures that stand along the walls.To the southwest is a black gate. North of the gate is a contact stone. To the north there is a gout of flame blocks the passage that leads to the room beyond. A creature can jump over the flame easily, but might get burned. Slightly to the west of the gout of flame is a rough cavern pathway which may or may not lead the the room beyond. 

Around the huge crucible are a Red Wizard (his robes look slightly different from the other Red Wizards you have seen and is represented on the map by a C) and two Thayen Apprentices. There as also a large redish creature working with the boiling metal in the crucible.

 The Wizard looks overs and shouts Intruders, attack them.

Everyone roll initiatives 

Red Wizard's initiative 5

Thayen Apprentices' initiative 5

Reddish creature's initiative 14

 Anyone with an initiative of 22 or higher can act.

 The bigger crates and piles of armor (each object that takes at least most of one square) as indicated on the map are big enough to provide half cover to any medium sized creature, and the space is not occupiable, for either moving through, or ending your turn in. The same goes for the crucible, but it also provides half cover to the large  reddish creature. The smaller roundish objects (takes up less than and square for each individual object) are considered different terrain.

(To learn about the reddish creature you need to make a Religion check.)

Velmine Initiative: 20

Initiative 13

Eiren initiative: 21