Jensen Ackles on His Supernatural Reunion on The Boys (Exclusive)

Jensen Ackles is reflecting fondly on his time on Supernatural.

From 2005 to 2020, the actor, 47, fought demons, ghosts and monsters as lovable bad boy Dean Winchester on the cult classic TV show, and “it was lightning in a bottle,” he tells PEOPLE.

When the series ended after 327 episodes, it became the longest running North American sci-fi series in history, and it still remains beloved amongst fans.

“I don’t think we ever, ever thought that it would become what it has become,” says Ackles. “It is a phenomenon. I wish I understood the formula. I don’t know that there is a formula for that. I truly feel like it was just a lightning strike, and I’m proud — and will forever be proud — of being a part of it.”

Five years later, he and costars Jared Padalecki, who played his brother Sam, and Misha Collins, who played the angel Castiel, remain close.

“We see each other more often than you would think — honestly, at least once a month,” Ackles says.

Recently, Padalecki and Collins even joined Ackles on set of the upcoming fifth and final season of The Boys playing guest roles, the details of which are still tightly under wraps.

“It was weird. It was like inviting my friends over to somebody else’s house for dinner,” Ackles says. “I was like, ‘Listen, guys, don’t make me look bad. I got to stay here.’ They were amazing. I can’t wait to talk more about it because it was quite an experience.”

Though he has wrapped filming on The Boys, Ackles will soon step back into his character Soldier Boy’s suit to film the prequel series, Vought Rising, this summer.

“It is an odd departure from the world of The Boys,” he says. “I’ve only had a few scripts in my pocket, so I know vaguely where we’re going, but I’m thrilled.”

While a release date for season 5 of The Boys and Vought Rising hasn’t been set yet, fans of Ackles’ can currently catch him in Prime Video’s new crime drama Countdown.

When a Department of Homeland Security officer is murdered, his character, LAPD detective Mark Meachum, is recruited to a top-secret task force to find the killer.

“I connected with Meachum’s work ethic,” he says. “He figured out a way to make things happen on his own. And there was a humor to him that I connected with, or maybe I brought that to him.”

While Ackles prides himself on staying active to “capitalize on fight scenes” in his projects, his life at home in Connecticut with his wife, Danneel, 46, their daughter Justice, 12, and their 8-year-old twins Zeppelin and Arrow is much less demanding.

“I’ve got a really, really quiet, peaceful life,” he says. “When I go home, I’m home. I’m not Jensen the actor. I’m Jensen the husband, the dad, the friend, the brother, the son. I think having that stability in my personal life has really given me a good grounding, a good foundation for what I do.”

Thanks to Supernatural, there’s not much that can make him sweat.

“We’d spend nine and a half months filming 23-episode seasons,” says the actor. “It was a marathon.”

So, with Countdown, a “13-episode season feels respectful,” he deadpans.

Countdown is now streaming on Prime Video.