Star Wars: The Clone Wars - Season 3 Episode 17 -

The Jedi remain stranded on Mortis, and the Son aligned with the Dark Side of the Force renews his efforts to convert Anakin as the Jedi prepare for a decisive confrontation. To turn Anakin to the Dark Side, the Son shows Anakin future images of himself causing so much pain and death as the Sith Lord Darth Vader. This works, and Anakin joins the Son out of fear that what he saw would actually happen. Ahsoka disables the ship upon hearing that Anakin joined the Son, and leaves to help Obi-Wan find the Father. The Father later confronts Anakin and erases his memory of the terrible vision the Son had shown him. When the Son tries to kill the Father, the Father steals the sword and uses it to kill himself, taking away his Son's power, allowing Anakin to kill the Son and restore the balance.