Darth Vader #5 wrapped up the new series' first story arc and it delved into how the Sith Lord first got his hands on the red lightsaber he used to strike down Obi-Wan Kenobi. In a surprising twist, the in-canon story revealed that those who turn to the Dark Side must steal their lightsabers from a Jedi and corrupt the Kyber crystal within for their own blades so they can fully wield the Force. What a twist!
After slaying Jedi Master Kirak Infil'a, he set about creating his lightsaber and was ordered by Emperor Palpatine to go to the spot where Anakin Skywalker "died" on Mustafar to build it. It was during that moment Vader had second thoughts about being a Sith and used the green blade to strike down his Master. After finally ridding the Galaxy of evil, he tracked down Obi-Wan to beg him for forgiveness.
Well, that's what happened in Vader's Force Vision anyway! After waking up from his hallucination, Vader declares that "This is all there is." However, this moment of clarity could have a major impact on the Star Wars Universe moving forward and explains why he ultimately found redemption in Return of the Jedi. Could this have an impact on Kylo Ren's journey? We'll find out in Star Wars: The Last Jedi!