( I don't own Star Wars, or any other franchise, the music and photos from online not mine)
( Starblade Eternal by Bjorgmas plays as looking at the fleet above Remnant.)

The forest of Vale so lively and some areas untouched by human or faunas. Grim large and small felt the new invaders as wave after wave sent to crush this new foe.
A beowolf alpha howled in the forest rallying others to be silenced and disintegrated followed by the sounds of familiar gunships and walkers. "Nice shot Din." Cara dune said to her partner as they pushed towards an area of interest the scanners have picked up unusual grim activity from the fleet above Remnant.
Her and Din free spirits in the galaxy to an unknown planet fighting alongside guardians, new republic, mandoliorns and this world's military known as ATLAS, sure a few squads were with them but the information they provided more intel on these creatures. Even guardians with their carbines and many weapons she's heard them calling them Sith experiments that are not contained, their arrival with the sounds of the AT-TE firing its main gun as indirect fire alongside the gunships, ATRTs and the ground pounders with the new republic and mandaliorn expedition units on the ground. Every so often a small contingent of winged Grimm would attempt to attack the unit but the combined Arms including Star fighters to the Grimm were fighting harder and harder to protect this area of interest.
Every so often the unit would hear a distinct shot of their sniper rifles they've picked up on the grim spying on them from a distance. What the Grimm still not getting a chance to learn to defeat the new foe even intelligence by the jellyfish ones watching are being picked off by the Coalition snipers before they even have a chance after they started advancing into the forest from the village they rescued they noticed they were being watched then in a few minutes immediately counter attacked by the Grimm. With the unit realizing this it quickly standard practice to eliminate those Grimm immediately spotted.

A hour later they came to the mouth of a cave large and untouched except fresh Grimm charging out of the dark mouth into the earth. The Grimms red eyes providing targets for the men and women and illuminating the cave with countless blaster bolts finding their targets. "This is Cara Dune, fleet I request a squad of armored droids to explore this cave we're at. We don't know what's down in there." Cara requested beside Din on her com as he covered her.

( if you read the last book these were introduced, now the single gun replaced with a mini gun, wrist rockets in one arm, vibro swords built into the wrist, a feature to self destruct still optional depending on mission when deployed, from ship boarding to brute force elimination of targets, heavier lighter armor, only the Guardians of the Republic has access to these due to protocols put in place that insures they can't be reprogrammed at all.)

( by the unknown numbers of droids made in the Clone Wars it's possible to find just countless numbers unused.) (the commando droids got upgraded too, carrying thermal Detonators, better tracking and optic hardware and getting updated with newer manufacturing by the guardians)

"Cara dune this is fleet command repeat what you're seeing?" On her com the guardian fleet responded with, "Command I'm looking at the mouth of a cave that keeps spewing out Grimm as we speak and we will loose our tactical foothold here and I'll not risk our men to go down the unknown." Cara responded back as part of the Coalition formed a circle that blocked the cave too while constant sound of battle raged against the Grimm. Before even reaching this place the Atlas infantry had ran out of ammunition and were borrowing E11s from their new allies till they were resupplied. "This is command you'll get your reinforcements." Fleet command responded with before the direct line was off.

Three modified HMP gunships descended from the clouds their light swivel guns laying down fire alongside other fighters in the air on the mounting Grimm counter attack. With each one that rearmed the Guardians new rockets were being fielded too, area denial air burst rockets raining shrapnel in a devastating molten fragments with destruction giving the unit on the ground time to breath alongside the other Uwings and LAATs in the Air. The three droid gunships quickly dropped off their cargo six Hammers and twenty four commando droids to back the hammers. "Push into the cave and find what's in it and report back." Cara ordered the commander commando droid "Roger Roger" the commando droid commander responded then a simple gesture to the cave the unit pushing into the cave.

The unit of droids pushed deeper into the cave till the found the source as fresh Grimm where climbing out a massive lake of black jell like substance. The droids continued eliminating Grimm all around them, the hammers with better sensors were able to capture evidence Grimm climbing out of the pool and promptly eliminated by the unit of droids. The commando's overheating their blasters resorted to their vibro swords their fast and accurate actions and armor keeping them in the fight a little while longer.

In the city of Vale Ezra and Sabine walk with headmaster Ozpin, General Ironwood, professor Glynda Goodwitch , Qrow, specialist schenne and teams RWBY and JPNR. "General by today's accounts there's a bigger game at play on Remnant. A war that the public doesn't see right now." Ezra comments to the group. Ozpin stops cold and the ones in his inner circle give each other an eye of these visitors know something is up before their own do. "What would mean by that General?" Yang asked crossing her arms leaning on the railing. "The guardians and Mandaliorns both have generations of warfare in experience, the Guardians preferring more off the record, black ops of black ops or missions so dangerous that they shouldn't return but we do time and time again we're just MIA if one of us fall." Ezra responds to Yang then Sabine chims in "My husband is right on us Mandos in experience and we've been Conquerers, manipulated by hidden foes even our planets some never the same again by the wars we've raged. My armor alone is 500 years old." The response was cut short by Ezra's com beeping and he raised his wrist up to answer it and Cara Dune appeared the sounds of battle raging around her and in the background Din making sure she's protected. "Ezra the droids found something interesting, sending their feed now to you" Cara tells him before he can respond but what the ones watching the interaction and him see the feed from the HAMMERS fighting off waves of fresh Grimm crawling out of the black goo pool as fast as they're being eliminated. "This is one of their origin points. Droids initiate self destruct protocols as close as possible to that pool or in it." Ezra orders without hesitation seeing one commando droid fighting Grimm with its fist and sword. The feed cuts including their hologram to Cara.

Back at the raging battle against the grim the droids self destructed sending hot explosions through the tunnels and the proton bombs In the hammers immediately incinerated the pool Grimm goo to the very crack it originated from and glassed the whole inside as hoards of Grimm were running out they were engulfed by the wall of fire instantly incinerated them and their mist and at the mouth of the cave it sounded like a large jet engine followed by flames coming out of the mouth and any other tunnels and crevices anything in sight immediately turned to ash. The formation as the sound of blaster fire died down some Grimm walked forward still burning to only collapse a few feet as the flames consumed them.
Republic gunships circled the mountain observing as other tunnels were exposed by the flames any Grimm that was inside or near the mouth of the cave wouldn't have survived. As the silence feel over the battlefield rumbling was heard followed by the tunnels including the cavern caved in sealing the underground network forever.
"This is Cara Dune, mission accomplished ." She reported in the comms as Grimm started fleeing the area in fear.

The dark island legends of remnant talk about for eons sat a queen an immortal woman on her throne. Her queen of the Grimm felt pain through her body feeling the birthing place of her Grimm one them being painfully severed. Her inhuman scream rang through her dark castle her arms sweating and feeling like they were on fire then it stopped. Sitting on her throne she looked over the landscape and across the ocean mind reeling from what happened the possibilities she hadn't felt this powerless before. "A new threat as entered the board." Salam breaths out.