Harvey Guillén wants his 'What We Do in the Shadows' character to team up with Buffy the Vampire Slayer in season 3

• Harvey Guillén told Insider that he wants Guillermo to lean into his vampire slayer heritage.
• Guillén plays Guillermo on FX's "What We Do in the Shadows," based on the movie of the same name.
• The actor also said he wants Sarah Michelle Gellar to "come out of retirement" for the FX show.

Harvey Guillén revealed that he wants his character Guillermo on FX's "What We Do in the Shadows" to embrace his vampire slayer birthright on the upcoming third season.

"I would love for the storyline to maybe go in a direction of where Guillermo leans more into his Van Helsing heritage and meets a real Slayer," Guillén told Insider in a recent interview.

The actor, who plays the human familiar to a narcissistic vampire on FX's horror comedy, also stars in the new film "Werewolves Within," which focuses on a small rural town besieged by a mysterious predator that turns out to be a werewolf.

But while Guillén's most recent project features a terrifying lycanthrope, he told Insider that he was drawn more to vampire movies and TV shows - especially Sarah Michelle Gellar's character on "Buffy the Vampire Slayer," whom Guillén previously said he'd love to see guest star on the FX show.

"It'd be like, here comes Buffy! And Buffy comes out of retirement to help him and pass over the baton of being the Slayer," Guillén said of his vision for the "What We Do in the Shadows" and "Buffy the Vampire Slayer" crossover episode.

"They'd be so cool fighting evil side-by-side," he continued. "Who knows, the possibilities are endless. Just get Sarah Michelle Gellar to the show."

Guillén even said he'd seen fan art of his character Guillermo and Gellar's Buffy - two of TV's most iconic vampire hunters - fighting monsters together.

"There's some really cool work where like, someone put Buffy and Guillermo back to back fighting an army of vampires," the actor told Insider. "I saw it and I literally got little goosebumps because I was like, 'This is so cool.'"

In early June, news broke that season three of the hit FX comedy would be premiering on September 2. The second season ended with Guillermo's vampire roommates becoming aware of his skills as a Slayer.

While Guillén wasn't able to share any specific plot points about season three, he told Insider that the new episodes would pick up "right where" the second season left off - and for fans to expect a mysterious Siren as well as guest stars "from the past."