The Knights of Ren
To be clear, the actual nature of the 'Knights of Ren' is based entirely on educated guesses and assumptions at this point. Supreme Leader Snoke mentions the group in passing, and the images of masked men glimpsed in Rey's Force Vision have supplied the rest of the illustration, with most assuming they are warriors either serving Kylo Ren, or fighting beside him in service to an unknown person.
It's almost guaranteed that the Knights of Ren will be explored and featured in the coming Episodes, hopefully explaining their different weapons and helmets, and if their possible allegiance to Kylo Ren is due to his lineage, or just a mutual reverence to Darth Vader. But almost as soon as the movie was released, die-hard fans made two big assumptions: that the shots of the men in black were, indeed, the Knights of Ren, and that the slain bodies surrounding them are those of Luke Skywalker's new (former?) Jedi apprentices.
That's just as likely to be proven true as any other theory, but there are some problems: the film plainly states that Kylo Ren was trained by Luke before betraying him, but it's never explicitly stated just how many students Luke actually had before Ben Solo turned to the Dark Side, or what ages they happened to be (children, or adults?).
Remember: Palpatine and Vader carried out a near-complete annihilation of the Jedi in Episode III, leaving only Luke, Yoda and Obi-Wan alive - although several remaining Jedi were also shown to have survived in Star Wars: Rebels. It's true that Luke and Leia aren't necessarily the last Jedi that will ever be found, but the assumption that Luke would be able to singlehandedly search out, investigate, and recruit not some, but dozens of Jedi children, while technically possible, isn't actually stated in the film.
Whatever the details or frequency of potential Jedi being born across the galaxy in the years since Return of the Jedi, it's a large leap to think Luke managed to not just find dozens of promising students, but would risk training each and every single one of them singlehandedly. Misdirection is also a factor worth considering, since fans needed nothing more than a shot of scattered dead and the mention of a "Jedi Temple" to fill in the gaps with Expanded Universe tropes.
The result: the creation of a straightforward, seemingly obvious interpretation of the Knights of Ren scene - and if J.J. Abrams and company were using their heads, it wouldn't be a hard reaction to predict. But let's take imagination out of the equation a bit, and look at the most basic, simplest explanation based on what is actually shown: Luke trained Ben Solo, who went rogue, gathered other elite warriors to his side (and cause?), and went... somewhere, to kill... someone.
But what is the ONE mission we know Kylo Ren probably had to carry out? The retrieval of Darth Vader's helmet. When fans remember how the Empire's last excursion onto the moon ended (in total defeat), it makes sense why Kylo Ren would need some back-up (in the form of skilled warriors, not large, bulky vehicles).
When those same fans remember which adorable race of aliens managed to defeat the Empire with spears, stones and falling logs - and the relatively small size of the dead (initially seen as children) surrounding the Knights of Ren in Rey's flashback - the actual tragedy could be something else entirely...
Were the Ewoks Slaughtered?
We hate to state this theory as much as Ewok fans hate to hear it, but the evidence is hard to dismiss. On closer inspection, the images of the Knights of Ren show virtually dozens of dead surrounding them, and few of them appear to be adult-sized beings. Sure, it could be Luke's young Jedi (and a few older Jedi or innocents caught in the crossfire), but that conclusion is based almost entirely on new assumptions.
On the other hand, we know that Darth Vader's helmet had to be retrieved at some point, we know that it was laid to rest on Endor's moon, we know that the Ewoks reside on that moon, and are vicious to outsiders. We also know that the dead didn't need to be taken down by lightsabers, since only Kylo Ren is shown to be using one - the other Knights of Ren are all carrying blasters, staffs, or other standard weapons that would have an advantage over a primitive race.
The fact that the moon's dense forests clearly have an active rain cycle, along with the many rocks and melee weapons visible scattered between the bodies - not sporting any discernible clothing - make the more logical conclusion the saddest one. It's also the simplest: Kylo Ren sought out Vader's helmet, went to Endor with back-up, and killed anyone who got in their way.
If you ask us, that's definitely the kind of cruel and unjust slaughter that would disturb the Force enough for Rey to sense it.
The fact that some have claimed to see Kylo Ren holding a second lightsaber is also explained by this theory. Some had concluded that the lightsaber he held was Luke's, having vanquished his students, and him, before the former Master fled into hiding. The connection to Luke, were that the case, would justify this scene's inclusion in Rey's first Force encounter. But if Darth Vader was buried with his own saber, and it too was collected by Kylo Ren, then the significance would be just as strong.
Vader's saber is never actually shown to be destroyed or lost in the showdown with the Emperor once his hand is cut off, and in the end, it's not necessarily a massive plot point. That being said, Kylo Ren completing his training and finally using his grandfather's lightsaber in combat against Luke Skywalker, or his daughter, would be a fantastic thematic pay-off for the previous two trilogies.
But it wouldn't bring back the Ewoks. And considering how willing J.J. Abrams was to tear out the hearts of fans by killing off a beloved character in Episode VII, the cruel culling of the walking teddy bears seems like an even more painful follow-up.
That's our theory on the Knights of Ren mission teased in Rey's vision, but the nature of the group, and their overall role in the coming films is still an unanswered question. We hope skeptics will agree that it's best to focus on what the evidence of the movies actually suggests at this point, but if you have your own theory or interpretation of the visions, be sure to let us know and discuss them in the comments!
Star Wars: Episode VII – The Force Awakens is now in theaters, followed by Rogue One: A Star Wars Story on December 16th, 2016, Star Wars: Episode VIII on May 26th, 2017, and the Han Solo Star Wars Anthology film on May 25th, 2018. Star Wars: Episode IX is expected to reach theaters in 2019, followed by the third Star Wars Anthology film in 2020.