I think something like this would be cool for Kane, I made this up but would be amazing if it happens.
During a backstage segment, Seth Rollins verbally abuses Kane again and leaves.While Kane's getting all angry like he normally does, a voice off camera says "Brother...", Kane looks off camera, closes his eyes and looks down and the camera fades.Later that night during a Seth Rollins segment, the flames explode, slow chemical plays and Kane comes sprinting it out with the Mask and everything and destroys everyone in his way.