Syntax

Per the venue description, this is appropriately spelled ‘Nar Shaddaa’.

Nar Shad[d]aa

First, the ‘they had insisted’ and 'long a thorn in his side' portions works better as an aside and thus should be an em dash. Ideally, you limit the em dashes though, so you could try something like the below.

They had insisted the intel was good and according to the coordinates, Lithar Andaris [—] long a thorn in his side [—] would be somewhere nearby.

Unnecessary comma before the word ‘and’. There is no need to split two independent clauses with a comma if you already have the word ‘and’ separating them.

Frustration threatened to boil to the surface and so he knelt [...] "Leave now and keep your life."

This is a sentence fragment. You must have at least one independent clause and neither of the below is it. The first sentence has no verb. The second sentence is dependent on the first. This is a sentence fragment, therefore this comes off as very awkward.

The minds of hopeless beings, and the miasma which their toils and troubles bore.

This is a nice descriptor, but it should not be in quotes. Rather, you should make it italic to denote a sound.

UNNGGH!

Though this does not take away from your syntax score, the hyphen should be an em dash. Em dashes are great for asides such as ‘one which narrowly saved his life’.

The Force, in his concentration, had offered a frantic warning [—] one which narrowly saved his life.

The hyphen and the name afterward are not necessary since you refer to him as the ‘would be assassin’. You can simply delete it.

Had they been capable, his molten eyes would have burned a hole through his would be assassin.

This isn’t a word in the English dictionary and google can’t find it. Perhaps you meant a different one?

Lithar's ultimatum was simple, the scar on his face a badge of [villeity] and resolve.

Story

This is a good, but I find myself wanting to know more about the myriad of other noises. This would help paint the scene better and pull me into the story. As it stands, this is lackluster at best and a wasted opportunity to lay out the scene even further. This is especially true since before this sentence you mention “such cacophonies were truly overwhelming”.

The strange purr of his respiration drew no attention, drowned out by a myriad of other noises.

Much like the above, I am glad that you informed the reader of the reason this fight is taking place, but you still neglect to explain why Lithar has been a thorn in Thanadd’s side. This could help me understand the fight a lot better.

Tonight, he would complete his assignment. The intel was good, they had insisted, and according to the coordinates, Lithar Andaris - long a thorn in his side - would be somewhere nearby.

Nice description.

Nar Shaddaa's intestinal labyrinths

I like that you write Lithar attacking from above, which works well with his character, but the reader in never told how Thanadd finds the Lieutenant Colonel. One moment we are told that Thanadd is dodging for his life and then in another we are told that Thanadd has found him. The “how” this happens is missing. This is a gap in the story.

The Lieutenant-Colonel was perched upon a second story balcony, wordlessly peering at the pillar in black armor.

Realism

Lithar has his Athletics at +0, which is not accurate with the below statement. The sentence below would require at least +2 Athletics.

Breaking his fall by scaling the debris, Lithar rolled unharmed to the paved street below.

A Juggernaut’s Iron skin feat works by shrugging off an attack, not ramming a pillar. The sentence below uses this feat improperly.

He cried out as he smashed into the support pillar, cracking the frame and forcing Lithar to ditch his weapon.

Syntax

The word highlight below is spelled ‘millimeters’ not 'milimeters'. In addition, Human should be capitalized.

He missed Mawgath by few [millimeters], but it was enough to distract the Pau'an and make him miss the [H]uman, who quickly jumped back.

The possessive ‘The’ should be in front of the the ‘Dark Jedi’s lightsaber’. Otherwise, it sounds awkward.

[The] Dark Jedi's lightsaber left a long mark on the street.

Change out ‘him’ with something more specific like ‘Thanadd’. Another alternative to fix this issue is to simply say 'he daunted'. In addition, you don’t need ‘the Lieutenant Colonel. At this point, we know the combatants.

"You were not even close," daunted [Thanadd].

The sentence is incorrect. Adding the word ‘are’ fixes it.

"I missed you this time, but how long [are] you are able to run, coward?

This is a tense issue. ‘Moved’ should be ‘move’.

"We shall see," replied Mawgath angrily, but he did not move towards his enemy. This sentence just needed something between ‘Standing’ and ‘few meters’; otherwise, it sounds very awkward. Standing [a] few meters from the Dark Jedi Knight, Lithar saw that as an opportunity to get rid of his enemy

The correct spelling is ‘human’. In addition, though ‘dream about a better moment’ is not grammatically incorrect and thus doesn’t hurt your syntax score, I recommend that you use [of] rather than [about].

The [Human] was sent to Nar Shaddaa to prevent a member of Clan Tarentum from hiring a group of mercenaries for a raid and he could not dream [of] a better moment to complete his mission.

This sentence is very awkward, but I understand what you are trying to say. First, the use of ‘surprisingly to himself’ is best re-arranged to modify the word ‘hesitated’, as in he was surprised that he hesitated. This makes the intent of the sentence much clearer. This is not a grammar issue, so no hit to your syntax score for this specific mention. BUT, there is a syntax mistake later in this sentence. The word ‘a’ needs to be between ‘for’ and ‘few seconds’.

[W]hen he aimed at the Pa'aun and was right about to shoot, he [surprisingly] hesitated for [a] few seconds, afraid of missing his target and killing someone else.

Thoughts are not put in quotes. You should use italics.

What if I kill an innocent passerby? It would not be planned and it might cause severe troubles, even in a place like Nar Shaddaa, thought the Lieutenant Colonel.

Story

Good job taking advantage of the plot hole left by your opponent and filling it in with your own reasons. With this sentence, the reader finally understands kinda what the conflict is taking place.

The himan was sent to Nar Shaddaa to prevent a member of Clan Tarentum from hiring a group of mercenaries for a raid and he could not dream about a better moment to complete his mission.

Realism

Lithar aspect titled ‘According To The Plan’ clashes with the statement below. Lithar should have taken any innocents into account. This is further backed up by the aspect ‘To The Tiniest Detail’.

Surprisingly to himself, when he aimed at the Pa'aun and was right about to shoot, he hesitated for few seconds, afraid of missing his target and killing someone else. "What if I kill an innocent passerby? It would not be planned and it might cause severe troubles, even in a place like Nar Shaddaa," thought the Lieutenant Colonel.

Syntax

Unnecessary comma. For the first two, the ‘and’ by itself is fine for separating two items. For the third, it is just superfluous since you pause with the ellipsis. For the fourth and fifth, it is simply not needed.

This was the power of the Dark Side and the towering black knight relished it.

Hubris had distracted the Dark Jedi from simply ending the man's life and now he paid for his arrogance with his hand.

Your terror however....feeds me.

[...] as the light began to leave his eyes he focused what remained of his vital forces to pull the trigger.

Gasping for air, he fell from the awful grip to the street below with little fanfare.

In addition, this should be three dots, not four.

Your terror however...feeds me.

The comma should be a period since you start a new sentence without any additional words after this dialogue.

"Yes, soldier, yes. Your fear is your weakness. You would protect these...peons[.]"

Story

I like this imagery of rage and berserker a lot. Nicely done.

He saw nothing but red as he rushed the recovering Lithar, a berserker with little but a death wish.

Realism

This entry depicts Lithar dodging Mawgath’s lightsaber and then being caught by the Tarenti. Why isn’t the weapons specialist shooting? Then later on in your post, you mention that you are choking Lithar, but that he does not immediately react to this action by firing the weapon he is holding in his hand. When cornered you tend to defend yourself. Also, according to Lithar’s character sheet, his aspect ‘Bothans Do It From Behind’ would not have Lithar standing in close quarters facing his enemy.

Mawgath fed Lithar a lumbering swing of his lightsaber, anticipating the Lieutenant Colonel's reflexive tactics. His fist became a claw as the human changed levels, trying to dodge the blade. A massive gauntlet clicked against armor as the Tarenti gripped his opponent's throat, the crushgaunts a cold vice on his windpipe.

Thanadd Mawgath was too busy gloating to realize he had not yet disarmed his opponent.

Syntax

This is a comma splice. One way you could fix this is to change the comma to a period and then start the dialogue on its on line.

He shook his head and looked at his opponent, who angrily shouted at the Lieutenant Colonel[.] [enter][enter] "You will pay!"

This sentence needs an [A] at the beginning, as well as one before the word 'berserker'. You should also include a comma after the introductory ‘A few seconds later’.

[A] [f]ew seconds later[,] the Dark Jedi rushed at the Human in [a] berserker rage.

This is a tense issue since the fight is still ongoing. Rather, you can use ‘would be’ instead of ‘was and then this will work. Additionally, the correct phrasing is ‘more or less’.

None of them [would be] able to continue the fight for much longer, as both of them were exhausted and received [more or less] serious wounds.

You need an ‘a’ between ‘had’ and ‘few’. Otherwise, the sentence is awkward.

However, the Lieutenant Colonel was aware that he was far more tired than his enemy, even though the Pau'an had [a] few of his fingers rendered useless by a blaster shot.

The possessive ‘the’ is needed before ‘Dark Jedi’s head.

The Human aimed at his enemy and opened fire. He hoped to finish the battle with one clean shot at [the] Dark Jedi's head before it would be too late, but his hand was shaking a bit and he missed.

The correct tense, in this case, is ‘ran’.

He did not have a chance to shoot for the second time as the Pau'an simply [ran] into him and knocked him over.

The possessive of Lieutenant Colonel is with an apostrophe s. In addition, you need to state the owner of the ‘only working fist'. I suggest you use ‘his’ instead.

The Dark Jedi hit the Lieutenant Colonel'[s] face again and again with [his] only working fist.

This sentence just needs a possessive ‘the’ where indicated.

He continued to beat him long after breaking [the] man's jaw and nose and making all [the] man's teeth fall out.

Realism

Thanadd is in the middle of his rage. He will not be exhausted until after the rage subsides.

None of them was able to continue the fight for much longer, as both of them were exhausted and received less or more serious wounds.

This is his second miss in a row, and he hasn’t really hit anything this entire match beside a point blank shot to Thanadd’s hand. This is out of character with a weapons specialist at +4, who should rarely miss.

The Human aimed at his enemy and opened fire. He hoped to finish the battle with one clean shot at [the] Dark Jedi's head before it would be too late, but his hand was shaking a bit and he missed.