<P> As part of his storyline, the character later returns to evil after unwillingly becoming the new Source . As the Source, Cole is eventually vanquished by the Charmed Ones, only to come back from death itself in his attempts to win Phoebe back . By this point he is one of the most powerful beings to ever exist . Driven insane, Cole is, through his own doing, once again killed by the sisters in the fifth season . When the character returns for a guest appearance in the seventh season, it is unclear what kind of being he is, but he states that he is caught somewhere between life and death, atoning for his sins . </P> <P> Cole Turner makes his first appearance in the third - season (2000--01) premiere episode, "The Honeymoon's Over". Charmed Ones Phoebe (Alyssa Milano) and Prue (Shannen Doherty) run into Assistant District Attorney Cole Turner at the site where they killed a demon, and cover their tracks . Over the course of the episode, it becomes apparent to the audience that Cole is himself a very powerful demon, pursuing Phoebe romantically and deceiving the sisters as to his true nature in order to finally kill them . </P> <P> In "Power Outage", Cole's superiors, the demonic Triad, learn that he may have developed genuine romantic feelings for Phoebe; Cole responds by killing them, forcing him into hiding . Meanwhile, the sisters acquire a target in the red - and - black - skinned demon Belthazor (Michael Bailey Smith). In "Sleuthing with the Enemy", the Charmed Ones discovers Cole and Belthazor are one and the same, but when Cole convinces Phoebe that he, being half human, truly loves her, she fakes his death so that her sisters Piper (Holly Marie Combs) and Prue will not hunt for him . </P> <P> When Cole re-emerges, causing a rift between Phoebe and her sisters, he attempts to re-ingratiate himself with his demonic peers, the Brotherhood of the Thorn, as the sisters' double agent . When Prue and Piper are both killed following a successful mission by the Source's assassin Shax (Michael Bailey Smith) in the season finale "All Hell Breaks Loose", Cole begs the Source (again, Michael Bailey Smith) to turn back time and prevent the exposure of magic . The Source agrees on the condition that Phoebe remain in the Underworld under his command, though he secretly orders her to be killed . Shax attacks the Halliwell Manor once more after time is reversed, but this time Leo (Brian Krause), Piper's husband who is also the sisters' guardian angel (whitelighter) is not available to heal either Piper or Prue, who lie gravely wounded . </P>

When do they find out cole is balthazar