The Star Wars franchise is perhaps the biggest in the entirety of pop culture and has lore that is so vast and expansive; it is hard keeping up with it. The iconography all throughout the franchise is insane, the Galaxy seems endless in terms of exploration, the characters are excellent, and the various groups throughout the Galaxy likewise.
There are so many groups in the franchise from the Rebel Alliance, to the CIS, to the Jedi and Sith themselves. One fascinating and mostly unexplored group that has popped up over the past couple of years thanks to Chuck Wendig's Aftermath trilogy and The Rise Of Skywalker is the Acolytes Of The Beyond.
DARK SIDE FANATICS
The most obvious and the core fact about the Acolytes of the Beyond is that they are dedicated, obsessed, and in a state of worship to the Dark Side of the Force and the Sith.
They are non-Force sensitive themselves and call themselves the shadows. The Acolytes of the Beyond regard everyone as being slaves to the Force, seeing it as a river of power that only those on the Dark Side of the Force could change the current of as the Sith are not victims of fate.
EXISTED DURING THE GALACTIC CIVIL WAR
The fact that the Acolytes of the Beyond existed during the time of the Galactic Civil War is obvious if you know about Chuck Wendig's Aftermath trilogy, but is nonetheless interesting.
With Palpatine and Vader, the only Sith in existence during this time, it is fascinating that the Acolytes of the Beyond were carrying out their purpose, and existing with their beliefs at this time.
NETWORK OF CELLS
The Acolytes of the Beyond were not just one or two people in a concentrated area fantasizing about a Galaxy ruled by the Sith. They networked, they had cells.
This is similar to the rebels who had cells such as the Ghost crew. There are far more Acolytes of the Beyond than we are currently aware of, no doubt, and the fact they carried out their work through these cells is fascinating.
YUPE TASHU
These cells had to have leaders to take the cells to complete their objectives, maintain their beliefs. One such leader was Yupe Tashu.
Yupe Tashu is not a well known Star Wars name. Tashu was one of Palpatine's advisors, one of his closest. He was a historian of the Dark Side of the Force and a Sith cultist and was a big part of the Acolytes of the Beyond following his escape from prison.
ATTACKED & RESISTED THE NEW REPUBLIC
The main enemy of the Acolyte of the Beyond was the New Republic, who following the fall of the Galactic Empire. That makes sense considering their infatuation with the Sith and the Dark Side.
Their tirade against the New Republic included attacks on various small outposts of the New Republic. One such attack included one led by the earlier mentioned Tashu, who led a twenty-four person cell on Devaron to attack a small Republic outpost.
OCHI WAS AN ACOLYTE
The Rise Of Skywalker introduces fans to Ochi. Ochi was a Sith assassin hired by Palpatine to capture Rey and bring her to Palpatine and ends up killing Rey's parents, who later died on Pasaana after being tracked by Luke Skywalker and Lando Calrissian.
Ochi was also a member of the Acolyte of the Beyond. Nothing is known about Ochi's time with the group as he debuted in The Rise Of Skywalker rather than Aftermath, but he will likely get some sort of exploration in the future given his role in Rey's life.
RECEIVED DREAMS FROM FALLEN SITH
Through the entire known existence of the Acolytes of the Beyond, in terms of the current standing canon, there are only ever two Sith at a time. That being up until the 'death' of Palpatine, at which point there were none (really one in Palpatine).
Therefore there is an entire back catalog of Sith, a complete history of the Sith Order. Some of this catalog appear to members of the Acolytes of the Beyond in dreams, or Force visions. Details are sparse on these dreams or these Sith, but it is fascinating that there were Sith who appeared to these fanatics.
ENTRANCED BY SITH ARTIFACTS
The Acolytes of the Beyond are unsurprisingly well versed in the lore and history of the Sith. They are fanatics, after all. Alongside the various Sith Lords across history, the group was obsessed with Sith artifacts, similar to Palpatine's fixation with them.
They saw items such as Sith lightsabers, helmets, and other pieces of certified Sith memorabilia to have held Dark Side powers within them. Artifacts are a cool and seemingly largely unexplored aspect of the new canon and hopefully are explored more with characters such as Doctor Aphra.
STOLE LIGHTSABERS FOR SACRIFICE, THEN USED THEM
Continuing on the subject of the Acolyte's obsession with the Dark Side and Sith artifacts, the Acolytes were transfixed with Sith lightsabers and used them for sacrificial purposes.
The Acolytes stole lightsabers intending to reunite Sith with them in death. Later though, the group just started using the lightsabers themselves, rather than destroying them, as a way to take a stand against the New Republic.
THEY BELIEVED THEY HAD DARTH VADERS LIGHTSABER
Darth Vader has one of the best and most iconic lightsabers in the Star Wars universe. As was the trend with the Acolytes, they adored the idea of getting the lightsaber and destroying it to return it to Vader in death.
A junk trader on the planet Taris named Ooblamon claimed to have the lightsaber of the Dark Lord of the Sith, so the Acolytes, of course, purchased it. However, Ooblamon was unsure if it did belong to Vader, it is still currently unknown if it actually was Vader's blade.