Warning: spoilers ahead for Darth Vader #6!
In the latest issue of Marvel Comics' Vader's borderline treasonous acts, but also the inner turmoil and conflict he senses within his apprentice.
Vader just wanted the truth in digging up his past, not exactly knowing what he would discover. The Emperor had lied and withheld the information of Pé's death from him, letting him believe that it was immediate, resulting from his anger. After venturing to very personal worlds tied to his past such as Tatooine, Coruscant, and Naboo, Vader makes his way to Polis Massa, where Pé died after giving birth to Luke and Leia. While Vader does find records, they are incomplete (meaning he doesn't yet find out about Leia). What he does find are the last words of his wife, believing that there is still good in him, despite the horrors he had already unleashed in his first days as Vader. Naturally, this causes major conflict within Vader, which angers the Emperor upon Vader's return.
In Revenge of the Sith. However, this time, Vader must rebuild himself. Not only that, but he'll also have some significant limitations.
The Emperor tells his wayward apprentice that he is not permitted to use the Force. If he does, the Emperor claims that he will know, and the exercise will come to an end, the implication being that that end would be Vader's own demise by his master's hand. With that, the Emperor leaves Vader to fend for himself. The issue also ends with the Emperor sending his secret Sith assassin Ochi of Bestoon to hunt Vader down, which will no doubt test the Dark Lord to his very limits.
The Emperor's testing of Vader in order to reteach him the path of the Dark Side is certainly a brutal one, though not entirely unexpected given the nature of Sith Lords. What is surprising is Vader losing his ability to use the Force during these trials. Vader will have to rely purely on his own primal darkness and rage, forging that into power that he might use to redeem himself in his master's eyes, becoming worthy to wield the Force once more. With Ochi of Bestoon on his tail, he better find a way to fight soon as Marvel's Darth Vader continues.