Anakin Skywalker is a human male born into slavery on Tatooine, freed by Qui-Gon Jinn, trained by Obi-Wan Kenobi, and turned by Palpatine. As Darth Vader he was introduced in Star Wars: Episode IV A New Hope (1977), performed by David Prowse and voiced by James Earl Jones; the prequel trilogy cast Jake Lloyd and Hayden Christensen as Anakin.
The seam
The interesting critical question about Vader is not whether the fall is convincing on film — reasonable people disagree — but what the books do with the twenty years between Revenge of the Sith and A New Hope. That gap is where the character actually lives in print, and the answers have varied wildly: a grieving man, a machine, a torturer, an apprentice waiting for his chance, a father who does not yet know he is one.
The comics own him
Marvel's Darth Vader runs since 2015 are the most sustained work anyone has done with the character in any medium. Kieron Gillen's run treats him as a middle manager in a hostile organisation, competing for the Emperor's regard and quietly building his own power base; Charles Soule's takes him back to the immediate aftermath of the suit. Both are essential and both are, in the best sense, procedural.
Legends
Star Wars Legends produced its own Vader canon — the Dark Lord novel, the Force Unleashed continuity, a secret apprentice, a whole hidden career. Almost none of it survived 2014. Read it as an alternate history rather than as prologue.
Why he still works
Because the redemption is not earned by argument. Nobody talks Vader out of it. He is moved by one specific person suffering in front of him, which is a much smaller and more human mechanism than the mythic scale of the films suggests — and it is the reason the ending lands.
