What tha kark!?
Kordath Bleu ran on light feet down one of the ruined corridors, moving around fallen masonry and statues that lay in his path. He'd been sent to Oricon to investigate and recover, not tangle with a walking bloody tank. This was not how he saw his day going. He could hear the booted steps of the armored warrior pursuing him, having said something to the man that he didn't care for. A sense of alarm ran through the Ryn, prompting him to duck behind an upright statue of some robed figure. As he did so, several slugs smashed against the ancient stones, sending splinters in all directions.
“Well, that was a wee bit too close,” muttered the Arconan. He peeked around the edge of his cover to see the black-clad figure taking measured steps with twin pistols raised. The report of said guns firing echoed down the hall, a whizzing sound as he pulled back telling him how close the shots had come.
Bleu crouched and looked for his next option for cover, wondering how many bleedin’ shots the man's pistols had in them. Running low on options as the footsteps grew closer, Kordath pulled a flash grenade from his jacket and waited, slowing his breathing. As he did, he gathered the Force to himself, taking advantage of his momentary safety and channeling the energy to the muscles in his legs.
“You can't hide back there forever. Come out and surrender!”
“Are ya karkin’ serious, mate!? Ya tried ta cut me bleedin’ 'ead off just now, no deal!”
Almost too low to hear through the mask, Kordath caught a, “Have it your way, then,” from the man.
The Ryn counted to five as the footsteps closed in, before tossing his grenade out of cover and down the hall. Before the thing even hit the ground, the Arconan was running with preternatural speed in the opposite direction, juking left and right to avoid the inevitable gunshots. A flash of light lit the corridor, throwing long shadows of fallen statues past the fleeing Arcanist and silencing the slugthrowers behind him.
Keiji was not a happy Togruta; the flash grenade had overcome his thermal imaging that he'd been using in the shadowy hall to track the fleeing threat. His vision went dark as the system overloaded and his helmet rang from the concussive shockwave that accompanied the flash of light. Not one to waste ammo, he stopped shooting and sidestepped towards the nearest wall, relying on his montrals to lead him to cover should the Ryn have a nastier trick up his sleeve. Nothing came, and as the ringing in his head stopped and helmet’s visuals cleared up, he saw and heard nothing but the faintest echo of running footsteps once more.
It didn't occur to the goal-driven Odanite that he may have overreacted; he had a job to do and the odd little Force-user was an obstacle in his path. The Clan needed whatever secrets and artifacts that hadn't been scavenged already for the inevitable conflicts ahead. At the least, they could keep them out of the hands of any Sith who'd use them against the outnumbered Jedi.
He set off in pursuit once more.
Kordath wasn't having a great day, either, stumbling through darkened stairwells and halls, trusting his Force fueled senses to lead him to safety. Instead, they lead him deeper into the old fortress, to an unassuming door covered in scratches and dents. Signs of past attempts to pry or batter it down. Focusing his sight, with some assistance from the Force itself, he could make out an aberration in a mural opposite of the door.
The mural, much like many in the fortress, was of some great battle scene of an ancient and forgotten war. What stood out was a featureless banner, which, to his Force-heightened vision, looked as if it protruded from its surroundings. Tentatively, the Ryn pushed it in with a gentle touch, and heard a click behind him and the sound of ancient gears turning.
“Huh,” said the Arconan as the door opened up, catching a glimpse of old, cube- and pyramid-shaped items on shelves. They glowed with inner light and power. “Well alright, not a wasted trip.”
A warning from the Force screamed down his spine, causing the Ryn to duck moments before a heavy crimson blade gouged part of the wall above him out.
“Kark!”
Syntax
Need a comma after the introductory phrase.
Repetitious use of "open" that doesn't add to the story in a meaningful way.
This section would have benefitted from em-dashes instead of commas to create a mental aside.
You need to be consistent. Either capitalize the race or don't, but not both. (Technically, it should have a capital as per the Star Wars race conventions)
Story
It took me a bit to remember you had thermal imaging on your helmet, which reduces your range of view. Should probably mention that in some way in your writing so it isn't so confusing.
You gave a good reason, or central motivation, for being there that certainly works for Kord as per his CS, but I am left wondering for more reasons as to Keiji's presence. There is no aspect that marks him as particularly interested in treasure or exploring, and it isn't really explained much in terms of story. Just a contact and a secret chamber. Not why Keiji is interested in that chamber. Then the fight suddenly starts at the tail end. It's a single attack. Why is Keiji attacking? Because Kord seeks the same thing he does? It isn't clear to the reader.
Realism
This was discussed amongst the staff a bit before this match came up for judgement. I'll explain much the same answer I gave then. While the montrals would certainly reveal movement to you, it is a form of echolocation and just gives you a sense of proximity to objects. Seeing as Kordath is not a Shadow, he can't move while in his Cloak. So, this is makes him stationary. So, you would know something should be there, perhaps. In terms of proximity, but not outright knowing there is a person here that he can't see. Especially when they are completely stationary.
So, to summarize that cause it got way too wordy, the Feat is clear: proximity and movement. Those are the only things revealed by the montrals.