Mary Cosby Is 'Happy to Be Back' on RHOSLC but '100 Percent' Stands by Her Decision to Quit the Show

Mary Cosby is officially back!

Two seasons after quitting The Real Housewives of Salt Lake City, the Pentecostal preacher returns to the Bravo series as a full-time Housewife when season 5 premieres on Wednesday, Sept. 18.

It's a homecoming that fans and Cosby are both celebrating.

"I'm kind of happy to be back, to be honest," Cosby, 51, tells PEOPLE. "Filming was like a whirlwind all over again, but it was a great experience because I formed real friendships this time around. So that was a real charm for me."

Viewers saw Cosby last season, in the Friend role. She had previously told Housewives EP Andy Cohen that she wanted to come back "to help you all out" — a comment many interpreted to be a dig at the show's uneven third season.

"My goodness..." Cosby says, when the remark is repeated back to her. 'That really was my state of mind! I really felt that's what I came back for, because they needed some personality; something to spice things up. I mean, why else would I have come back?"

Indeed, Cosby did bring a jolt of energy to the show, with her unfiltered remarks and disinterest in the drama earning laughs week after week.

"I didn't even know I was funny until I watched me. And then I was like, 'Wow, that is hilarious? This is how you behave?'" Cosby recalls. "But that's what makes me Mary, because I don't change for the camera. I can't fake it. I just have to be me. I'm not trying to be funny, but I guess it ends up being funny."

Still, the experience of being a Friend ultimately wasn't satisfying. "Oh, I don't want to ever be on the show as a Friend again. You just get left out of everything!" Cosby shares. "So I was like, 'I'm not coming back as a Friend. It's either full-time or I'm not coming back at all' because I just couldn't do it again."

Cosby doesn't bluff, something producers learned the hard when when she refused to show up to the RHOSLC season 2 reunion amid accusations that she was leading a cult, which she has denied.

Asked if she'd do the same again, Cosby didn't blink. "100 percent, I stand by my decision," she says. "I am glad I did what I did. I believed in what I felt, I believed in my choices and to this day, I have no regrets. If I could do it over again, I would do it over again."

As for what fans can expect to see from Cosby this season, the trailer showed her participating in activities far more than she ever has before, even zip-lining off a mountain and across a lake in one scene. The changes were so significant that costar Whitney Rose, a former rival of Rose's, boasted: "I f---ing love the new Mary!"

So... is there a new Mary?

"I've always been the same Mary, but yeah... I feel good in my body," Cosby says. "So I'm letting my light shine and running with that torch. That's all I know how to do: just be myself."