Despite the fact that Darth Vader has a reputation for being one of the most ruthless killers in all Star Wars history, there is one shortcoming that plagues him time and again–an unbelievable failure of which he will soon suffer the consequences.

While Anakin Skywalker was first introduced to unwitting fans as Darth Vader in Star Wars: Episode IV - A New Hope, he wasn’t always a dark lord of the Sith. Upon his origin story in Star Wars: Episode I - The Phantom Menace, Anakin was depicted as a sweet and brilliant kid. He was a natural pilot, inherently good-natured, and–most of all–a genius when it came to droids. In fact, Anakin was the one who built C3-PO (long before the droid betrayed him for those ‘rebel scum’), and he did it with just the incredibly limited resources he had access to. Ironic, it seems, that Anakin’s greatest skill would become his ultimate shortfall.

Related: Yoda Broke the Jedi's Ban on Attachment Long Before Anakin Skywalker

In Star Wars: Darth Vader #30 by Greg Pak and Luke Ross, the former handmaidens of Padmé Amidala are plotting to kill Vader as they wish to rescue another one of their sisters, Sabé, from his villainous grip. According to Vader, Sabé chose to join him as she saw the value in aligning herself with someone of such immense power, but the other handmaidens don’t believe it. Throughout the issue, they plot a final assault against Vader, all while Sabé secretly does the same. Previously, Darth Vader sent Sabé on a mission to kill Jul Tambor–someone who has evidently wanted Vader dead for some time. After Sabé pretends to kill him and then ultimately saves his life, Jul Tambor tells her that he has plans to kill Darth Vader, and he tells her just how he will do it: droids–more specifically, re-built droids Vader ‘killed’ in the past. Jul Tambor scoured the galaxy searching for droids Vader sliced to bits, but failed to destroy completely. These droids left behind informational data banks and video memory files depicting their fights with Vader–giving Jul Tambor an advantage in more ways than one.

Darth Vader’s Failure to Kill Droids is Literally Coming Back to Haunt Him

All the Star Wars droids Darth Vader killed.

Throughout his extended universe history, it is shown time and again that Darth Vader is terrible at killing droids. Like it’s described in this book, it isn’t that he can’t cut them down with his lightsaber, because he certainly does that, it’s that he doesn’t fully destroy them to the point where they are no longer a threat–something that is shocking coming from someone who is not only a cyborg himself, but also grew up building droids as advanced as C3-PO. Vader regularly left their memory storage intact and never bothered to obliterate the entirety of their droid bodies. In the past, this was just an observation made by fans, but now, this shortfall is coming back to haunt him. Not only has Tambor rebuilt these victims of Vader’s wrath and given them the means to have their revenge, but he’s also watched the video-memories of their previous encounters with Vader and studied his movements, fighting style, and–most importantly–his weaknesses.

While Star Wars fans know that nothing major comes from Jul Tambor’s plan as Darth Vader’s demise was already shown in Episode VI, this assault may very well weaken him, the Empire, and his chokehold on the galaxy–potentially being instrumental in the Rebellion’s ultimate victory. However, despite whether Tambor’s plan has any impact on Vader or not, it is still incredibly significant in terms of Star Wars lore as it not only highlights and confirms Darth Vader’s most unbelievable failure, but it’s making him pay for it.

More: Star Wars' New Droid Sidekick Is the Best Since R2-D2