The Salvatores and all their friends in Mystic Falls will have to gear up to face Evil herself when "The Vampire Diaries" returns for its eighth and final season of this fall.

During the 2016 San Diego Comic Con presentation, the people behind the supernatural drama series unveiled a trailer that looks back on the bad things that happened in the Mystic Falls. But toward the end of video, fans are warned that Evil herself will appear in the series for season 8.

During the show's 2016 SDCC panel held Saturday, executive producer Julie Plec revealed how they managed to come up with the biggest villain of the series to date.

"It's a new take on villains for us," the executive producer said, as reported by TVLine. "It's rooted back all the way to ancient times."

Writer Kevin Williamson also revealed that the new big bad will be the final nemesis of the Mystic Falls heroes. According to the writer, the introduction of the character is a "cool way to infuse Mystic Falls with this ultimate evil. It's like a cherry on top of the entire mythology of Mystic Falls."

But while the trailer did not mention more details about the upcoming Evil character who will be introduced in the series, TVLine revealed that "UnREAL" alum Nathalie Kelley has been tapped to portray the recurring role of Sybil, who is believed to be Evil herself.

According to the character description, Sybil is a "power monger who manipulates her victims 'into twisted games and tests for her own amusement and glorification.'" But in spite of her viciousness, Sybil is still a person who only wants to feel loved.

Meanwhile, Kat Graham revealed that the upcoming season will also feature the culmination of Bonnie's journey.

"A lot of last season was about the development of the relationship Bonnie had with Enzo, and obviously Bonnie and Damon," the actress said during the Comic Con panel. "You saw the crumbling of her in the finale. She also doesn't have her magic. The thing that made her feel like herself, and also her best friends, are not there. It's going to be really exciting to see Bonnie's journey this season."

"The Vampire Diaries" season 8 premieres on The CW on Friday, Oct. 21.