Razzle Dazzle Jumpchain AKA the Great Jumpini

From the introduction:

The last thing you remember was that your ten years were up, you waited for it to end, a sensation of passing and now, there's a bloody saw in your hands, the lights are shining in your face, thousands of faces staring at you raptly.

But before you can open your mouth in explanation they clap and cheer, as your bisected victim waves happily. Great Houdini's ghost, you're a magician Harry!