The Tro-Clon was a "confluence of events" which would bring about the purification or ruination (or both) of mankind. Its arrival was announced in the Nyazian Scrolls.
It is initially assumed that the Tro-Clon is a single event or an individual, though it is soon revealed to be, in fact, a confluence of events that seemingly culminate in Season 4 of the show. While the true extent of the Tro-Clon is never truly explained, it is possible that the Tro-Clon refers to the rise of Jasmine, as explained by Skip. According to him, there was a series of events going back years that had all been guided by Jasmine, working as a Higher Power, towards the single purpose of bringing herself to Earth.
- Fred and Lorne switching dimensions (Lorne's spell was necessary to "activate" Jasmine in an amnesiac Cordelia)
- The return of Darla
- Cordelia receiving the visions
- Birth of Connor
- Re-awakening of Daniel Holtz
- Holtz bringing Connor to Quor'Toth and Connor's return to this dimension "of age" to mate
- Cordelia's demonization and subsequent rise to a heavenly dimension
- The reign of The Beast and the destruction of Wolfram & Hart
- The temporary return of Angelus to aid in the destruction of The Beast.
- Rise of Jasmine