Hush moves out of the shadows to attack the guard engaged with Derek. Sliding in for a low hit, followed by a swift fist upwards at his chin.

Unarmed Attack: 14 Damage: 5

Bonus Unarmed Attack: 8 Damage: 8

Initiative: 20

Derek's Initiative: 10

(Forgive minimal formatting; I am currently on mobile.)

Initiative for the soldiers near Holden and Derek: 6
Initiative for the Spear near the Wilderling: 10
Initiative for the Corporal: 20

Capitalizing on the moment of surprise, Holden and Derek strike the two Spears hard! The one Derek attacked looks bewildered and is bleeding heavily from his wounds, while the one Holden attacked turns his surprise into anger at whoever had attacked him.

Wisdom save for the Corporal: 20

Luxaene takes the moment to hurl a bolt of arcane energy at the Corporal, but unfortunately, it harmlessly reflects off the polished metal, ricocheting into the forest.

The Corporal feels a hint of fear shiver down his spine, but he collects himself enough to see the gaunt Wizard before him. He yells, resisting the spell.

Hush, seeing Derek’s success, nimbly leaps behind the occupied spear. His first strike connects, and you hear a crack. The second strike misses, but that’s enough - the Spear coughs before crumpling to the ground, unmoving.

INITIATIVE ORDER: 
Holden - 21
Hush - 20
Corporal - 20
Lazarus - 19
Derek - 10
Spear next to Wilderling - 10
Luxaene - 8
Spear next to Holden - 1

Holden / Hush, make your move!

Hush runs towards the Corporal standing near his prisoner (max movement, as close as possible). He readies a dart as he moves and throws it as he's about to come to a stop, using his momentum to add to the dart's throw.

Dart Attack: 12 Damage: 7

(If my movement leaves me more than 20ft away, my throw would be at disadvantage, so here is an extra roll just in case 14)

Holden makes another strike at the spear he just attacked.

Attack: 17 Damage: 5

Derek moves towards the remaining imperial. As he does so he points at the imperial spearman and a pillar of flame erupts from the ground to engulf the unfortunate soldier.

Action - Derek casts Sacred Flame on the spearman. Dex Save 13 to avoid the hungry flames or takes 1 of fire damage.

Hush launches a projectile to the Corporal, but the recent turn of events has left him alert and on his best guard. Easily deflecting the dart thrown at him, the Imperial looks around, assessing the situation.

Holden connects once again with the Spear he is fighting. A jet of blood spurts from the impact, but the Spear still seems alive, albeit gathering his whereabouts from the surprising encounter he is in.

The Corporal, seeing one if his men crumple and the other grievously injured, wonders as to how well connected their prisoner is, and why anyone would help him. Readying his shield, he instructs to his subordinate to be on his guard, and will yell to the group - "Halt! In the name of the Imperium, I command you to cease combat!" after taking the Dodge action.

Dex save for the Spear: 10
Derek's flame connects, briefly singing the stunned soldier. Unfortunately, it does not affect him as much as you had hoped.

Lazarus, Luxaene, make your moves!

Luxaene hears the Corporeal's words. A smile appears as she flicks an outstretched hand to him and fires another bolt of arcane energy!

Eldritch Blast
Ranged Spell Attack: 15 Damage: 7 (force)

<For speed of gameplay, I'm going to post Derek's actions. Busy day at work and won't be able to check in much. Feel free to bot Derek as needed.>

Seeing the manifestation of this new fiery power contained within him and struggling to come to terms with it, Derek focuses on the weapons in his hands to see him through this confrontation. He moves to engage the Spearmen with the Corporal.

Action - Derek attacks the spearman with his short sword. Attack: 20, Damage: 8

Bonus Action - Derek attacks the spearman with his dagger in his offhand. Attack: 11, Damage: 3

Lazarus chuckles as he walks non-chantantly into the fray. He looks at the Corporal and says, "Well, you should've ran when you had the chance to. Now, your mortality shall be realized!"

He points at the Corporal and chants another dark incantation. A bell tolls faintly in the distance as the Corporal steps closer to the grave. 

Action: Cast Toll the Dead on Corporal. DC 14 Wis Save or take 3 damage if uninjured, and 1 damage if injured. 

(@Bizarre, wanted to clarify - there are two Spears currently alive; one is engaging with Holden and the other is next to the Wilderling and the Corporal. Map is updated - feel free to edit your actions to the intended target if you would like to change.)

 DM stuff:

 Luxaene, your bolt of energy just manages to seek out a gap in the Corporal's armor, and he gasps in pain as it connects!
Lazarus, your spell seems to have more effect this time around. It finds its mark and the Corporal seems to be in pain!

The Spear next to the Wilderling, seeing Hush attack his commander, will spring forward and make an attack at him with a spear! 
To hit: 18 dealing 3 piercing damage.

The Spear next to Holden looks to be in a pretty bad shape. Blood is gushing from various axe wounds, but nonetheless, he turns a spear towards his aggressor!
To hit: 18

The Spear just barely manages to graze the nimble Halfling, while the injured spear is too distracted by their wounds to connect an attack with the Half-Orc he is dueling with.

Holden and Hush, your move.

Must've triggered something while editing - none of the dice rolls are manipulated.

Holden smiles grimly as he stares into the fearful eyes of the spear, before driving his greataxe in a downward strike. 

Attack: 26 Damage: 12

Hush winces as the spear pierces him and he gasps from the pain. His breathing now laboured, he grits his teeth and attempts to crack the guard twice with the quick succession.

Unarmed Attack: 23 Damage: 7

Unarmed Attack: 12 Damage: 6

Holden's axe connects with a brutal swing, embedding itself in the unfortunate soldier's chest. He falls back with a sick slide, the life leaving his eyes. Hush's two blows connect in rapid succession, knocking the wind out of the Spear in front of him. The Spear looks around nervously, seeing quick work made out of the two soldiers ahead.

The Corporal, seeing the Spear being injured, will abandon his post near the Wilderling, and will attempt to Shove the Halfling down. 
Athletics check: 6
Hush, make an Athletics or Acrobatics check.

The WIlderling now makes its move. It will take its action to make a Sleight of Hand check to loose itself from its restraints.
Sleight of Hand: 14
Unfortunately, the WIlderling isn't quite able to escape the ropes that bind it.

Lazarus, Derek, your turn. 

Derek moves to Hush's aid as he flanks the Corporal. He attacks with his short sword and dagger once more.

Attack with Short Sword: 19, Damage: 6, Sneak Damage: 4

Offhand Attack with Dagger: 25, Damage: 3

Lazarus suppresses a laugh as he casts Toll the Dead at the Corporal again. DC 14 Wis Save, or 11 damage. 

Hush's Acrobatics Check: 10

Avoiding the shove from the corporal, he quickly lashes back with a punch to the corporal and a sweeping kick to the spearman.

Punch Attack: 17 Damage: 5

Kick Attack: 23 Damage: 6

Derek's attacks both land with sickening thuds, finding gaps in the Corporal's armor. He looks gravely injured as the blades exit their mark, wildly looking around for a means of escape.
Wisdom Save: 17
He makes a wild leap away from the fray, but a far-off sound of an ominous bell rings, and the Corporal crumples over, eyes rolling and limbs flailing. Hush takes this opportunity to catch the Corporal in the throat, ending his breathing, and he limply falls to the ground. He then sweeps the Spear of his feet, and the soldier hits the ground with a thud.

The Spear, seeing his friends and Corporal all perish, will hold out his hands and drop his weapon, a pleading look in his eyes. "Don't kill me! I was only following orders to capture an Outcast!"

The Wilderling will make another attempt to unbind itself from its ropes: 5
Unfortunately, it fails.

We're mostly out of combat - feel free to post in any order you would prefer.