Leon Oswald

An extremely talented French acrobat who comes to Kaleido Stage in the second season after being recruited by Kalos.

Leon comes across as very cold, self-centered, cynical, and rude. Despite his extraordinary talents, he has a terrible reputation within the circus and acrobatic community, and is infamously nicknamed the "God of Death." He got this nickname due to destroying every partner he's had, causing all of them to lead the stage.

It is later revealed that he had a sister named Sophie who died in a traffic accident after Yuri Killian tricked her in order to sabotage Leon and Sophie during the international Circus Festival. Yuri called her to a park far away from the stage so that she would be late and miss the show, but on her way back, she got into an accident, dying in the hospital by Leon's side shortly after. This event traumatized and changed Leon, causing his cold behavior.

By the end, Leon softens up and gets closer with the Kaleido Stage cast, thanks to Sora helping him fulfill his promise to Sophie and begin to move out of the past. Leon even apologizes to Sora for insulting Layla when they first met.