"Doctor Who" Season 10 is said to bring back villains not just from the past but also the Doctor's future evil self, Valeyard. Although details of the plot was not elaborated, it is enough to excite the series' hardcore fans for the comeback of the quirky science fiction series.

Valeyard first appeared in the 1986 episode of the series titled "The Trial of the Time Lord". Back then the Valeyard, played by actor Michael Jayston, was from the Gallifrey planet and a court prosecutor. However, the master reveals to the doctor that Valeyard is keeping a secret about his identity. That was when they discovered that Valeyard was, in fact, a reincarnation of the Doctor. "Somewhere between your twelfth and final regeneration." according to the reports.

If the series will follow the story from the 2015 Titan Comic Book series "Four Doctors", the 10th Doctor will team up with 11th and 12th Doctor. Although initially, the 10th Doctor didn't believe he has the 12th reincarnation, he hilariously thought 12th is The Valeyard. The story continues with "The Time of the Doctor" where a new cycle of regeneration is introduced and the Doctor exists in between the 8th and the 9th incarnation of the Doctor.

Steven Moffat, the series' showrunner, was in the recent New York Comic-Con last October 7 and he revealed that the last two seasons of "Doctor Who" has been darker. He explains that this is caused by Peter Capaldi's deeper and somber Doctor.

As of today, a total of twelve actors has played the role of the Doctor. The change of character from one actor to another is actually written in the storyline of the show. The show's concept is regenerating and reincarnating the Doctor by taking a new body and new personality as he travels time and the universe. Peter Capaldi now plays the Doctor after the exit of the last actor, Matt Smith, in 2013.