Paul Sloane is the Earth-Two version of Two-Face.
On the world known as Earth-Two, some time after Harvey Dent (Two-Face) was cured, a movie company heard his story and made a movie. Paul Sloane played the lead and while they were filming the part where Harvey gets a face full of acid, the prop man swapped the prop acid out for real acid because Sloane stole his girlfriend. Sloane was left horribly disfigured and followed in Dent's footsteps as a super-villain. Some years later, Dent would plead with and fail to redeem the second Two-Face, as Sloane had found his true calling as the criminal entity over his original failed identity. It is unknown if Sloane survived into old age during the time of the Crisis on Infinite Earths. Sloane was seen in the same criminal prison as was the Earth-Two Joker (Dent's face remained repaired, while Sloane's was not, suggesting that the Two-Face shown was Sloane). If he did, like all people of Earth-Two, Sloane was killed and erased from ever existing during the Crisis on Infinite Earths and succeeded by his New Earth counterpart as shown in Detective Comics #580.
In the current DC timeline, Paul Sloane is an actor who is hired by a group of Gotham's rogues to impersonate Two-Face. When the genuine article refuses to participate in one of their schemes (his coin having come up unscarred), Sloane is brought in as a replacement. Angered by this, the real Two-Face later captures and disfigures Sloane and the hapless actor is experimented on by the Scarecrow. Driven insane, he becomes a villain known as The Charlatan.
Powers and Abilities
Sloane had no superhuman abilities but was effective in planning out and executing elaborate schemes and tactics involving many criminal organizations.
Paul Sloane possessed the normal human strength of an average 6-foot, 180-pound man who engaged in regular physical exercise during his prime. His strength levels decreased as he got older.
Sloane has all the normal weaknesses of a human male. Sloane used a scarred coin to help him make planning decisions though unlike Dent really would make a decision flip in the execution of a plan which would be successfully used against Dent. Sloane used regular handguns and machine guns as an active criminal. It is the second Two-Face (Sloane) who is used as the archetype of the character in most of the later portrayals and alternate media over the original Two-Face who did not want to be a criminal. In the newspaper, that version is also an distorted actor named "Harvey Apollo", as well as the later revival of the character in the 1960s. The Sloane incarnation would be brought back in the New Earth reality as a pawn of Harvey Dent (originally in Detective Comics #580 and #581, and again Detective Comics #777). And as the Golden Age incarnation, the New Earth Sloane was disfigured when hired to play in the story of Two-Face. Intentionally disfigured by Dent, Sloane sought to outdo his predecessor same as the Golden Age Two-Face who because he was second Two-Face thinks of himself as far superior to the original. However unlike the Earth-Two incarnations, Sloane has not actually replaced the original Two-Face but merely supplements as the second one.While Dent was only Two-Face I of Earth-Two for a short period of time, Sloane remained as Two-Face II for most of his adult life. It is Sloane who has been the basis of most of the successive incarnations of the character despite the name and background of Dent used as the basis of the character. Two-Face is the primary personality to the point that he enjoys being Two-Face despite any opportunity to change back to his original persona which is the personal nature of Sloane, not Dent. Kent's butler Wilkins disguised himself as Two-Face before Sloane became the second true Two-Face in order to frame Dent for Wilkins' own crimes. But unlike either Dent or Sloane, Wilkins only wore makeup and was not insane. Thus Wilkins is not considered to be a true Two-Face. Unlike Dent, only Sloane's face was damaged. Sloane's hair was not distorted in color and remained completely black on both sides.