Kamen Rider Double Detective (Rider)

Kamen Rider Double Detective is the main and eponymous protagonist of the Neo-Rider Series Kamen Rider: Double Detective. Double Detective is the first Rider that transforms from two people.

Simon Holmes
The left half of Double Detective providing the 'body' (except when changing into FangJoker, where he becomes the 'mind') and a self-dubbed Hard-boiled Detective. Simon is also a Rider on his own as Kamen Rider Joker.

Charlie
The right half of Double Detective, providing the 'mind' (except when changing into FangJoker, where he becomes the 'body'), Charlie disappeared after being broken down into data but came back a year later, thanks to his mother and sister. Charlie is also a Rider on his own as Kamen Rider Cyclone.

Duo Rider
When Simon and Charlie set their Gaia Drives into the Double Driver Belt, Charlie's conscious mind enters Simon's body to produce Duo Rider (except when they change into FangJoker, where the opposite happens). Their quote at the start of a battle is "Now, count up your crimes!", a quote originally used by their predecessor and mentor, Sherlo Ishino.

When combined as Double Detective, Simon usually does most of the talking, though both speak when saying their pre-battle quote and announcing Maximum Drive attack names. When Charlie speaks by himself when transformed, Double Detective's right eye flashes. Double Detective's ability to function is dependent on the condition of both Simon and Charlie. If their synchronization is somehow disrupted, Double Detective will be unable to move properly. If their Rider form takes any significant amounts of damage, both of them will feel the pain after returning to normal and Charlie will often pass out due to his weaker constitution. Simon's habit of flicking his wrist carries over to Duo Rider.

Double Detective is unique among Riders in that rather than having explicitly defined forms, he instead has mix-and-match powers, this quality only being shared by Kamen Rider OOO. Through the different Gaia Drives, Double Detective has access to various combinations of powers, weapons, strengths, and weaknesses. Double Detective's forms accessed through their first six Gaia Drives are known as "Half Changes", due to the fact that Duo Rider can switch out one (or both) Gaia Drives in the belt in a "Drive Change" to change forms.

Each different version of Double Detective has its own finishing attack(s) known as Maximum Drives which is needed to defeat a Drivor. The energy imparted by the Maximum Drive does not destroy the Drivor but rather its Gaia Drive, resulting in the ejection of the Gaia Drive from the user's body, reverting the person to normal and the destruction of the Gaia Drive, hence why such a procedure is called a "Drive Breaker".