The original 'American Idol' Kelly Clarkson jumped reality show ships and kicked off the 'X Factor' results episode tonight (Nov. 23) by performing her new single 'What Doesn't Kill You (Stronger),' complete with graphic novel-type images flashing behind her. Our favorite? The fist that pumped while featuring words from the lyrics. She wasn't the only pop star to provide the entertainment on a tense episode. Crooner Bruno Mars also took the stage to show 'em how it's done.

Clarkson, wrapped in a beige bandage dress, is the original reality talent competition winner, so if there is anyone who understands the position the current crop of contestants are in, it's Clarkson.

We were sort of surprised that Clarkson didn't interact with judges Simon Cowell and Paula Abdul post-performance, since this was a reunion of sorts, as all three started off on 'Idol' together. Then again, the ep was only an hour and two acts were being sent home, so time was at a premium. That, coupled with the fact that Steve Jones is always cutting everyone off, meant no time for chatter.

At the midpoint of the show, Bruno Mars performed his new single 'It Will Rain,' with his signature hat and all. He stood on a riser and was drenched in red and orange lights at first. Then the lighting switched and began flashing to simulate lightning to match the lyrical content. It was all about Mars' voice during his performance of this heartfelt ballad.

Watch Kelly Clarkson Perform 'What Doesn't Kill You (Stronger)' on 'X Factor'

Watch Bruno Mars Perform 'It Will Rain' on 'X Factor'