Naturi Naughton, Joseph Sikora and the Cast of Power Celebrate Its 'Epic' 10th Anniversary: 'Long Time Coming' (Exclusive)

It's been 10 years since Power premiered, and the cast celebrated the milestone anniversary in style in New York City.

On June 6, Curtis "50 Cent" Jackson, Naturi Naughton, Joseph Sikora and Michael Rainey Jr. were on hand at the Hammerstein Ballroom to mark a decade since the Starz series hit the air — and to celebrate the premiere of the fourth and final season of its first spinoff, Power Book II: Ghost.

The cast of Ghost was also in attendance, with stars including Mary J. Blige, Method Man, Gianni Paolo and Woody McClain, along with some other familiar faces from the Power universe, Raising Kanan stars Patina Miller and Joey Bada$$.

Emotions were high, and Sikora, 47, tells PEOPLE, "The first and the most overwhelming feeling is that of gratitude."

"Anything that lasts 10 years, it's longer than most Hollywood marriages, so I'm really excited to be here and I'm so grateful," the star of Power Book IV: Force says, before sharing his gratitude to his former costar, who remains at the helm of the Power universe.

"I'm grateful to Curtis '50 Cent' Jackson for being the best boss I've ever had in my career, for being loving, kind, and accessible, and projecting my career to a next level, whether it was in the Power Universe or beyond."

Naughton, 40, similarly expressed her gratitude for the decade she's played Tasha St. Patrick as she said it feels "amazing" to be celebrating the anniversary and the final Ghost premiere.

"It feels like a long time coming, to be a part of something so epic. 10 years of creating something that changed the culture and just being celebrated," she shares. "It's really an awesome feeling."

The former 3LW member admits that it's "a little bittersweet" at the same time, though, as she prepares to "say goodbye" to her character after so many years. "When you think about all the fun, the friends, the memories, the joy — I became a mother on the show. I had my husband. So many things happened, and it really helped me become the woman I am. So it makes me feel proud," she adds.

Rainey Jr., who plays Naughton's son, Tariq St. Patrick, and leads Ghost, says it's "crazy" to be at the final premiere after spending close to half his life in the Power world.

"With me stepping into as the young kid I was, I really didn't know what I was thinking. It literally just grew, and it grew up in front of my eyes, as I was growing up," he says. "I'm grateful."

Naughton says she feels like her "child became a grown man" as she thinks back on the 12-year-old Rainey Jr. who joined Power, compared to his now 23-year-old self. "He became — from a little boy to a grown man, and I'm watching his growth and it's just been amazing, it's been beautiful," she says, adding, "I definitely feel like I mothered him throughout these years, and it's hard to let go."

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Both Rainey Jr. and his longtime onscreen partner in crime, Paolo, who plays Brayden Weston, feel ready for this chapter to end, though.

"People are saying it's the end, it's the final season, they're upset, but I'm just happy that I got to do this," Paolo, 28, says. "It really was a blessing every day. Every day, I had fun. And yeah, it's sad that it's coming to an end, but I'm more grateful that it just got to happen. So that's kind of the way that I'm looking at it."

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The season 4 premiere of Power Book II: Ghost is now streaming on Starz.