King Crimson

King Crimson is the Stand of Diavolo.

It is unknown when King Crimson was awakened in Diavolo, but it was assumedly some time after he became the boss of Passione.

It has a Sub-Stand, Epitaph, which in conjunction with King Crimson is also utilized by Diavolo's split personality, Doppio.

Appearance
King Crimson is a humanoid Stand. It has a white body with red armor on it, and on the red armor there are white stripes that go diagonally in both directions. King Crimson's face is super scary and Epitaph sits on his forehead. Lil' dude.

Powers and Abilities
King Crimson gives him the ability to erase time, meaning that for a certain period of time, the events are "skipped" and only the results of said events remain. Diavolo is able to manipulate fate in this way.

His Sub-Stand, Epitaph, lets him see five seconds into the future.

Trivia

 * The Golden Wind anime shows King Crimson's time-skip ability with a glitched effect, as if the animation itself has corrupted and skipped forward.
 * People often get confused as to how King Crimson works. I will not be explaining it to you.