The plot of Star Wars: The Last Jedi has been nothing short of mysterious, causing rise to a number of fan theories trying to piece together various footage and promotional materials into "conclusions." One such theory is the idea that the true villain of The Last Jedi will be revealed to be Luke Skywalker. This theory is backed mostly by the fact that posters and other materials show Luke in a nefarious pose and lighting that is more than a little reminiscent of how Star Wars villains are positioned on posters. Pretty thin. It's unclear if this is what Lucasfilm is actually planning to do, but I can tell them this: they shouldn't touch Evil Luke with a 10-foot lightsaber.
There's no real proof that Lucasfilm is planning to have Luke go dark or what that would even entail, but Luke's positioning on posters is suspiciously villainous. It's tough to cloak a guy in a hood with red and shadows and not think him a villain. Some of this would depend on the exact circumstances, but there are very few reasons why making Luke a villain is a good idea and a lot more about why it's a terrible one. Here's why Lucasfilm should avoid turning their flagship hero into the villain of Star Wars: The Last Jedi.
There Are Already Plenty of Evil Skywalker's
Haven't we reached our evil Skywalker quota by now? Turning to or being tempted by the dark side is a Skywalker staple, but there is such a thing as diminishing returns. Darth Vader famously fell from grace to become one of the greatest villains of all time, only to be saved by his son. Ben Solo, Luke's nephew, also couldn't deny the dark side and became the tortured Kylo Ren. Luke himself was once tempted by the dark side, but he learned to conquer his anger. It's all very much "been there, done that". It's hard to imagine a Dark Luke storyline that has more to say that anything that was already said by Vader. The Last Jedi already has Ren, Snoke and the First Order as villains anyway. Plus, hasn't Leia been through enough without her own brother going rogue?
Evil Luke Isn't As Exciting As It Might Sound
Star Wars has entered a rejuvenated period where there are a number of exciting potential storylines. Evil Luke Skywalker is not one of them. While there are certainly effective storylines about heroes becoming villains in fiction, Star Wars has made that particular trope its bread and butter. People are always shifting from light to dark and vice versa. Perhaps there is something to be mined from revealing Luke to be a villain, but this is already well-worn ground. We've seen it all before, and a morally complicated Luke would at least be more interesting than a straight-up villain. It would far more exciting to save that screentime for something fans haven't already seen in a Star Wars movie.
There's Already Been An Evil Luke
Mark Hamill is quoted as being interested in playing an evil clone of Luke Skywalker at some point. This is actually something that already happened, though, it's not canon any longer. In the Star Wars Expanded Universe, a clone of Luke was created from the hand that Darth Vader chopped off in their first duel. Said clone, who was named Luuke Skywalker (which speaks to the creativity on display for this whole thing), battled Luke but was ultimately killed by Mara Jade, Luke's non-canon wife. It made Luke do some soul searching, but that's about all the storyline accomplished. It's not really a stand out Expanded Universe tale, and maybe there's a reason for that. While I don't want an evil Luke storyline, if you're going to go for it, then you might as well go for it all the way and not cop out with a "it was a clone the whole time."
It Could Ruin Luke's Legacy
It almost goes without saying but: Luke Skywalker is one of fiction's greatest heroes. The tale of the young farmboy rising up and becoming a savior wasn't new when Star Wars first hit theaters, but Luke's hero's journey has cemented itself into our minds and culture as an inescapable classic. To make him into a villain is to sour that legacy and undo a symbol of goodness. Star Wars is full of characters who flip moralities on a regular basis, but Luke is an example of hope for the galaxy, that anyone can fight for what's right. It's one thing to make him conflicted or disillusioned, but full on dark side is too far. You wouldn't make Superman evil. You wouldn't make Harry Potter evil. Why would you make Luke Skywalker evil?